You have split glucose in two, balanced oxidation with reduction and you have made two moles of ATP per mole of glucose.
"You've completed the pathway.
Do you want
f"&Start Again"
"E&xit"
"Cancel"
startagain
"Exit"
continue
continue
You've completed the pathway. Do you want to start again or exit?
&Start Again
E&xit
Cancel
Start Again
startagain
ade two moles of ATP per mole of glucose.
Basic
Basic
You can distribute the unmodified material freely and modify it to your own requirements. However, we ask the following:
1. By all means give yourself credit for your work in your books but please leave this page unaltered in this book.
2. It is important that teaching material of this kind is disseminated as widely as possible, so please ensure that your material is also freely available.
3. Please send a copy of any modified or expanded versions of this program to Jon Maber, Department of Biochemistry & Molecular Biology, University of Leeds, Leeds, LS2 9JT , Tel 44 532-333134 Fax 44 532-333167.
Internet bmb6jrm @gps.leeds.ac.uk
default
buttonUp
buttonUp
default
Continue
continue
Basic
Pyruvate (2 moles)e
Excellent. You have regained the ATP which was invested at the start of the pathway. You have also got very close to the target of lactate. Because this step involved spontaneous rearrangment of enolpyruvate to pyruvate there is a very negetive DG, making it irreversible. This gives you a very useful control point.in the pathway.........
continue
buttonUp
buttonUp
C = OOOOOH
CH33OH P
O- PPPPP
C = O - PPPPP
continue
Buttons Used In The Following Pagess
ExitProgram
"This
appears
)the
, will
tutorial."
f"Continue"
buttonup
buttonup
This button, when it appears at the bottom of the page, will exit you from the tutorial.
Continue
backPage
"This
appears
)the
, will take you
where
were.
It can be used repeatedly
backtrack
%far
?want."
f"Continue"
buttonup
buttonup
This button, when it appears at the bottom of the page, will take you back to where you were. It can be used repeatedly to backtrack as far as you want.
Continue
NextPage
"This
appears
)the
, will take you
f"Continue"
buttonup
buttonup
This button, when it appears at the bottom of the page, will take you to the next page.
Continue
Move to the next step
Backtrack
Start Again e first page of
Exit to Windows
Animate
"This
appears
)the
, will
appropriate animation."
f"Continue"
buttonup
buttonup
This button, when it appears at the bottom of the page, will run an appropriate animation.
Continue
Animate
Animates the graphics on that page that page
Hotwords - These are words that are scattered round the text and are shown in italic, bold, underlined type and are larger than the surrounding text. They become active when the mouse operated cursor is placed over them. Try pressing this Hotword now!
-- Puts the sentence
quotation marks
a dialog box which can be removed
Hclicking
"Activating a HOTWORD will present you
dthat may contain definitions, references, hints
tips, prompts
other forms
encouragement."
f"Continue"
buttonDown
buttonDown
Activating a HOTWORD will present you with a dialog box that may contain definitions, references, hints and tips, prompts or other forms of encouragement.
Continue
Go on to the next page by clicking the
button below:
"This
appears
)the
, will take you
title
f"Continue"
buttonup
buttonup
This button, when it appears at the bottom of the page, will take you to the title page.
Continue
backtrack
buttonup
buttonup
^|backtrack
startagain
buttonup
buttonup
startagain
buttonup
buttonup
continue
buttonup
buttonup
D j
That's possible but not such a good idea. Later you will cut your six carbon molecule in two using aldol cleavage.
When a monosaccharide is subjected to aldol cleavage you get two monosaccharides. If you oxidise you won't have a monosaccharide anymore and the products of cleavage won't be both monosaccharides either.....
Oxidation of Glucose
Possible but not desirable!
H - O - C - H
C=OOOH P
- C -- RR3
O = C - HHHHH
C=OOOH P
- C -- RR3
HHHHHHHHHHHHH
Generalised Aldol Cleavagee
Dephosphorylation
In the simplest form a phosphate group is replaced with a hydrogen atom to give a hydroxyl group. The usual biochemical shorthand for the phosphate group is a P with a circle around it.
The DG for dephosphorylation of an alcohol is usually very negative and can be coupled with another energy requiring process such as phosphorylation of ADP.
Programmer ommision - couldn't carry out your request
Reduce
Programmer ommision - couldn't carry out your request
Introduction
The aim of this exercise is to help you understand the processes which occur in (anaerobic) glycolysis.
Starting with glucose you will choose the reaction types in sequence which will achieve the desired end point. I.e.:
1) Glucose converted to lactate.
2) ATP generated.
3) Oxidation balanced with reduction.
backtrack
buttonup
buttonup
^|backtrack
startagain
buttonup
buttonup
startagain
buttonup
buttonup
continue
buttonup
buttonup
Strategy
You will need to use some imagination to get something out of this exercise. If you memorise the sequence of reactions from the text book and simply enter them, you will learn very little. In fact you will find that you will learn more from choosing the wrong reactions! Each time you choose the wrong reaction type a page of text will tell you whether the reaction is impossible, undesirable or simply not the way it has evolved. More important, it will tell you why.
Hopefully you will discover that glycolysis is not simply a series of chemicals which you must memorise but a finely optimised system for squeezing energy out of glucose which has evolved over billions of years.
backtrack
buttonup
buttonup
^|backtrack
startagain
buttonup
buttonup
startagain
buttonup
buttonup
continue
buttonup
buttonup
The Task Ahead
Although lactic acid has the right empirical formula for a monosacharide carbon 1 is more oxidised and carbon 3 is less oxidised than the closest monosacharide - glyceraldehyde. So you need to split glucose into two three carbon monosacharides and then rearrange. oxidised and carbon 3 is less oxidised than the closest monosacharide - glyceraldehyde. So you need to split glucose into two three carbon monosacharides and then rearrange.
backtrack
buttonup
buttonup
^|backtrack
startagain
buttonup
buttonup
startagain
buttonup
buttonup
continue
buttonup
buttonup
HC = OOOOH
H - C - OH
CH2-OHPPPP
HO - C - HH
CH3-OHHPPP
C = OOOOOH
O- PPPPP
Glyceraldehyde:
Lactic Acid:
You just took off a phosphate. Why put it back?
To get from pyruvate to lactate you need to change the carbonyl group on carbon 2 to a hydroxyl group. 2 to a hydroxyl group.
Phosphorylation of Pyruvatenolpyruvateeeeeate
No Way!
It doesn't have a phosphate group to shift!
Phosphoryl Shift of Pyruvatenolpyruvateeeeate
Impossible reaction!
It doesn't have a phosphate group to remove!
Dephosphorylation of Pyruvateeeeeeevateeeeate
Impossible reaction!
That can't be done!
You've already oxidised once and will have to reduce once to balance up the oxidising agent you used (since this is anaerobic fermentation).
Oxidising again is not on.th inorganic phosphate.
That's why you're trying to isomerise to glyceraldehyde.
your money!!
Coupled Phosphorylation and Oxidation of
Pyruvateeolpyruvateeeeeate
No Way!
That can't be done!
You've already oxidised once and will have to reduce once to balance up the oxidising agent you used (since this is anaerobic fermentation).
Oxidising again is not on.th inorganic phosphate.
That's why you're trying to isomerise to glyceraldehyde.
your money!!
Oxidation of Pyruvateen and Oxidation of
Pyruvateeolpyruvateeeeeate
No Way!
Aldose - Ketose Isomerisation
HC=OHH P
H - C - OH
C = OOOOOH
CH2-OH P
That can't be done!
You've already oxidised once and will have to reduce once to balance up the oxidising agent you used (since this is anaerobic fermentation).
Oxidising again is not on.th inorganic phosphate.
That's why you're trying to isomerise to glyceraldehyde.
your money!!
Oxidation of 2-phosphoglycerateeation of
2-phosphoglycerateeeeeeate
No Way!
2-phosphoglycerate
Shifting the phosphate was a very good idea. It will help you with the next step.e
buttonUp
buttonUp
continue
2-phosphoglycerate (2 moles)
Good. You now have two moles of this for each mole of glucose.
buttonUp
buttonUp
continue
Glyceraldehyde 3-phosphate (2 moles)
HC = OOOOH
H - C - OH
CH2-O- P
Glucose 6-phosphate
HO - C - HH
buttonUp
buttonUp
continue
Good! By phosphorylating glucose you have put a charged 'handle' onto the molecule at one end.
You've also got an irreversible step at the start of the pathway which is another good idea. This would make an ideal point for a control step.
H - C - OH
H - C - OH
HC=OHH P
CH2-O- P
H - C - OH
You have put on a phosphate group without the need to use up ATP. Very well done!
buttonUp
buttonUp
continue
1,3-bisphosphoglycerate (2 moles)
C = OOOOOH
H - C - OH
CH2-O- P
O- PPPPP
Aldose - Ketose Isomerisation
continue
The phosphate does need to come off.
However, if you put it off until nearer the end of the pathway you can arrange for an irreversible step to close the pathway.
For the moment the task is to remove the hydroxyl group from carbon 3.
Dephosphorylation of 2-phosphoglycerateeeeate
Possible, desirable but off the pathway!
That can't be done!
You've already oxidised once and will have to reduce once to balance up the oxidising agent you used (since this is anaerobic fermentation).
Oxidising again is not on.th inorganic phosphate.
That's why you're trying to isomerise to glyceraldehyde.
your money!!
Coupled Phosphorylation and Oxidation of
2-phosphoglycerateeeeeeate
No Way!
Yes, you will need to reduce at some point. If you're to reduce with NADH you need to make a double bond first by dehydrating though.
You need to think about which hydroxyl group you want to remove when you dehydrate.
Reduction of 2-phosphoglycerateeeeeee of
1,3-bisphosphoglycerateate
Off the pathway!
You're already down to a three carbon molecule - you don't to cut it up any smaller.
Aldol Cleavage of phosphoenolpyruvateeeeeeeeeeeeeeeeeeeeeesphateg
No Way!
Click on the
backtrack button......menu.....
startagain
buttonup
buttonup
startagain
buttonup
buttonup
backtrack
buttonup
buttonup
^|backtrack
reaction!
You've done the dehydration you can't do another.
Dehydration of
Phosphoenolpyruvate
osphoenolpyruvate
No Way!
You've got one on. You don't need another.? Perhaps you should think about getting one of them off?
Phosphorylation of Phosphoenolpyruvateeeeeate
Now that you're nearly there it's time to take off the phosphate - no need to move it around.
If you take it off now the enol pyruvate will instantly rearrange to pyruvate and this gives you a very negetive DG and therefore an irreversible step.
Just what you need. Backtrack and dephosphorylate.
Phosphoryl Shift of Phosphoenolpyruvateeeeate
That can't be done!
You've already oxidised once and will have to reduce once to balance up the oxidising agent you used (since this is anaerobic fermentation).
Oxidising again is not on.th inorganic phosphate.
That's why you're trying to isomerise to glyceraldehyde.
your money!!
Coupled Phosphorylation and Oxidation of
Phosphoenolpyruvateeeeeate
No Way!
That can't be done!
You've already oxidised once and will have to reduce once to balance up the oxidising agent you used (since this is anaerobic fermentation).
Oxidising again is not on.th inorganic phosphate.
That's why you're trying to isomerise to glyceraldehyde.
your money!!
Oxidation of Phosphoenolpyruvateetion of
Phosphoenolpyruvateeeeeate
No Way!
Oxidation
HC=OHH P
Oxidation of organic molecules is often in the form of dehydrogenation. Two atoms of hydrogen are removed and a double bond forms.
Hydration may be involved before or after dehydrogenation.
desirable but not optimal!!!!!
You're already down to a three carbon molecule - you don't need to cut it up any smaller.
Aldol Cleavage of Pyruvatenolpyruvateeeeeeeeeeeeeeeeeeeeeesphateg
No Way!
This isomerisation converts between monosacharides.
You don't have a monosacharide since you oxidised so this is not possible.
Aldose to Ketose Isomerisation of
Pyruvate
lpyruvate
Impossible reaction!
This isomerisation converts between monosacharides.
You don't have a monosacharide since you oxidised so this is not possible.
Ketose to Aldose Isomerisation of
Pyruvate
ruvate
Impossible reaction!
To get from pyruvate to lactate is not a dehydration. You need to change the carbonyl group on carbon 2 to a hydroxyl group.
Dehydration of Pyruvate
lpyruvate
osphoenolpyruvate
Immpossible!
That can't be done!
You've already oxidised once and will have to reduce once to balance up the oxidising agent you used (since this is anaerobic fermentation).
Oxidising again is not on.th inorganic phosphate.
That's why you're trying to isomerise to glyceraldehyde.
your money!!
Oxidation of 1,3-bisphosphoglyceratee of
1,3-bisphosphoglycerateate
No Way!
Yes, you will need to reduce at some point but it might be better to take off one of the phosphates and make some space first.
Reduction of 1,3-bisphosphoglyceratee of
1,3-bisphosphoglycerateate
Possible, desirable but off the pathway!
There isn't an easy way to dehydrate - you need adjacent carbon atoms one carrying a hydroxyl group, the other a hydrogen.
It wouldn't help you isomerise to glyceraldehyde anyway.
Dehydration of Dihydroxyacetone phosphate
No Way!
C=OOHH P
CH2-O- P
CH2-OH P
glycerate
Impossible reaction!
Could be done but where does it lead? The only free hydroxyl group is on carbon 2. That would be removed by a dehydration. If you remember the target is lactate which has a hydroxyl group on carbon 2.
To get access to the hydroxyl on carbon 3 you will need to do something with the phosphate.phates first.
Dehydration of 3-phosphoglycerateeeeeeate
You've just taken one off. Why put it back? Perhaps you should think about getting one of them off?
Phosphorylation of 3-phosphoglycerateeeeeeate
No Way!
Yes you could easily take it off now. Glycerate is a charged molecule so will interact with enzymes well.
However, if you leave it on for the moment and link its removal to the formation of a carbonyl group you will have the advantage of an irreversible step near the end of the pathway.
Just shift it over to carbon 2 for now.
Dephosphorylation of 3-phosphoglyceratehosphate
Possible, desirable but not optimal!!!!!
That can't be done!
You've already oxidised once and will have to reduce once to balance up the oxidising agent you used (since this is anaerobic fermentation).
Oxidising again is not on.th inorganic phosphate.
That's why you're trying to isomerise to glyceraldehyde.
your money!!
Coupled Phosphorylation and Oxidation of
3-phosphoglycerateeeeeeate
No Way!
That can't be done!
You've already oxidised once and will have to reduce once to balance up the oxidising agent you used (since this is anaerobic fermentation).
Oxidising again is not on.th inorganic phosphate.
That's why you're trying to isomerise to glyceraldehyde.
your money!!
Oxidation of 3-phosphoglycerateeeeeeeeee
3-phosphoglycerateeeeeeate
No Way!
Yes, you will need to reduce at some point. If you're to reduce with NADH you need to make a double bond first by dehydrating though.
You need to think about which hydroxyl group you want to remove when you dehydrate.
Reduction of 3-phosphoglycerateeeeeee of
1,3-bisphosphoglycerateate
No Way!
You're already down to a three carbon molecule - you don't want to cut it up any smaller.
Aldol Cleavage of 2-phosphoglycerateeeeeeeeeeeeeeeeeeeeeeesphateg
No Way!
This isomerisation converts between monosacharides.
You don't have a monosacharide since you oxidised so this is not possible.
Aldose to Ketose Isomerisation of
2-phosphoglycerate
Impossible reaction!
This isomerisation converts between monosacharides.
You don't have a monosacharide since you oxidised so this is not possible.
Ketose to Aldose Isomerisation of
2-phosphoglycerate
Impossible reaction!
You've got one on. You don't need another.? Perhaps you should think about getting one of them off?
Phosphorylation of 2-phosphoglycerateeeeeeate
You've just done that. No need to shift it back.aps you should think about getting one of them off?
Phosphoryl Shift of 2-phosphoglycerateeeeeate
No Way!
You're already down to a three carbon molecule - you don't to cut it up any smaller.
Aldol Cleavage of Glyceraldehyde 3-phosphateFructose 6-phosphateg
No Way!
That is possible but it takes you further away from lactate. You need to keep the aldehyde group at one end so it can be oxidised to a carboxylic acid.
Aldose to Ketose Isomerisation of
Glyceraldehyde 3-phosphate
Possible but not desirable!
Glyceraldehyde is an aldose, not a ketose so this can't be done.her away from lactate. You need to keep the aldehyde group at one end so it can be oxidised to a carboxylic acid.
Ketose to Aldose Isomerisation of
Glyceraldehyde 3-phosphate
Impossible reaction!
Dehydration of Glyceraldehyde 3-phosphate
Could be done but where does it lead?
The only free hydroxyl group is on carbon 2. That would be removed by a dehydration. If you remember the target is lactate which has a hydroxyl group on carbon 2 so it may not be a good idea to remove it now.
Possible but not desirable!
It's about time you made a phosphate group without spending ATP.
You need to phosphorylate with inorganic phosphate. This requires energy input so it must be coupled with another process.
Phosphorylation of Glyceraldehyde 3-phosphate
Possible but not desirable!
That is actually a good idea because later you will want to remove a hydroxyl group from carbon 3 - tricky to do if there is a phosphate group stuck on it!
However, in glycolysis the shift of phosphate from carbon 3 to carbon 2 is done at a later stage. Sorry!
Phosphoryl Shift of Glyceraldehyde 3-phosphate
Possible, desirable but off the pathway!
It's best to keep a 'handle' on the substrate until near the end of the pathway...
Dephosphorylation of Glyceraldehyde 3-phosphate
If you oxidise the aldehyde group to a carboxylic acid that will get you closer to lactate but what about the ATP you need to make?
By just oxidising you could be wasting the free energy change for this process. You need to couple oxidation with phosphorylation.
Oxidation of Glyceraldehyde 3-phosphate
Off the pathway! y
To get closer to lactate you need to oxidise at carbon 1 and reduce at carbon 3. However carbon 3 has a phophate group in the way.
It might be better to think about the oxidation part first (and making ATP).
Reduction of Glyceraldehyde 3-phosphate
Off the pathway!If
You're already down to a three carbon molecule - you don't to cut it up any smaller.
Aldol Cleavage of 1,3-bisphosphoglycerateeeeeeeeeeeeeeeeeesphateg
No Way!
Click on the
backtrack button......menu.....
startagain
buttonup
buttonup
startagain
buttonup
buttonup
backtrack
buttonup
buttonup
^|backtrack
"Since
was a dead
you will have
backtrack.
Use the
f"OK"
continue
continue
Since this was a dead end you will have to backtrack. Use the backtrack button or menu command.
e backtrack button or menu command.
You've already got two phosphate groups on. Perhaps you should think about getting one of them off?
Phosphorylation of 1,3-bisphosphoglycerateate
That is actually a good idea because later you will want to remove a hydroxyl group from carbon 3 - tricky to do if there is a phosphate group stuck on it!
However, in glycolysis the shift of phosphate from carbon 3 to carbon 2 is done at a later stage. Try taking one of the phosphates off first.
Phosphoryl Shift of 1,3-bisphosphoglycerateate
Possible, desirable but off the pathway!
That can't be done!
You've already oxidised once and will have to reduce once to balance up the oxidising agent you used (since this is anaerobic fermentation).
Oxidising again is not on.th inorganic phosphate.
That's why you're trying to isomerise to glyceraldehyde.
your money!!
Coupled Phosphorylation and Oxidation of
1,3-bisphosphoglycerateate
No Way!
Reduction
Reduction of organic molecules is often in the form of hydrogenation. Two atoms of hydrogen are added across a double bond.
Dehydration may be involved before or after hydrogenation........
Possible but not desirable!
It's already well phosphorylated. There's really no need to phosphorylate more.
Phosphorylation of Fructose 1,6-bisphosphate
Possible but not desirable!
You've got the phosphate groups where you want them - one at each end. There's no need to shift them about.
Phosphoryl Shift of Fructose 1,6-bisphosphate
Possible but not desirable!
You've only just put them on - better leave them there.,
Dephosphorylation of Fructose 1,6-bisphosphatee
Possible but not desirable!
Good. You now have two moles of this for each mole of glucose.
buttonUp
buttonUp
continue
Glyceraldehyde 3-phosphate (2 moles)
HC = OOOOH
H - C - OH
CH2-O- P
Good. For each mole of glucose you have 1 mole of glyceraldehyde 3-phosphate direct from the aldol cleavage and now another mole from dihydroxyacetone phosphate.
So from now on there are two moles of each intermediate per mole of glucose processed.
Possible but not desirable!
You're already down to a three carbon molecule - you don't to cut it up any smaller.
Aldol Cleavage of 3-phosphoglycerateeeeeeeeeeeeeeeeeeeeeeesphate}
No Way!
You're already down to a three carbon molecule - you don't need to cut it up any smaller.
Aldol Cleavage of Dihydroxyacetone phosphateFructose 6-phosphateof[
No Way!ble reaction!
Oxidation
Reduction
dration of Dihydroxyacetone phosphate
No Way!
You're trying to isomerise to glyceraldehyde. Phosphorylation won't help that.
Phosphorylation of Dihydroxyacetone phosphate
Possible but not desirable!
No Way!
You're trying to isomerise to glyceraldehyde. The phosphate group is not in the way so it can stay where it is.
Dephosphorylation of Dihydroxyacetone phosphate
Possible but not desirable!
That can't be done!
Since dihydroxyacetone phosphate is a ketose there is no aldehyde group. You can't oxidise to a carboxylic acid and couple this with the formation of an acid anhydride with inorganic phosphate.
That's why you're trying to isomerise to glyceraldehyde.
your money!!
Coupled Phosphorylation and Oxidation of
Dihydroxyacetone phosphate
Impossible reaction!
That's possible but not such a good idea.
You're immediate aim is to isomerise to glyceraldehyde 3-phosphate. If you oxidise now one half will be more oxidised than the other.
Oxidation of Dihydroxyacetone phosphate
Possible but not desirable!
That's possible but not such a good idea.
You're immediate aim is to isomerise to glyceraldehyde 3-phosphate. If you oxidise now one half will be more oxidised than the other.
Reduction of Dihydroxyacetone phosphate
Possible but not desirable!
Phosphoryl Shift of Glucose 6-phosphate
Since you have just put a phosphate group on carbon 6 there is much point shifting it somewhere else.
Possible but not desirable!
Dephosphorylation of Glucose 6-phosphate
You've only just put the phosphate group on.
There's no point taking it off again.
Possible but not desirable!
That could be done. The aldehyde group could be oxidised and phosphorylated with inorganic phosphate to capture the energy.
However, if you split glucose into two first you can do this type of reaction on both halves later and double your money!!!!!!!!!!!!
Coupled Phosphorylation and Oxidation of
Glucose 6-phosphate
Possible but not desirable!
That's possible but not such a good idea.
At some stage you need to split your hexose into two equal halves. If you oxidise now one half will be more oxidised than the other.
Oxidation of Glucose 6-phosphate
Possible but not desirable!
That's possible but not such a good idea.
At some stage you need to split your hexose into two equal halves. If you reduce now one half will be more reduced than the other.
Reduction of Glucose 6-phosphate
Possible but not desirable!
Dehydration of Fructose 6-phosphate
The first stage of glycolysis involves splitting glucose into two equal halves.
If you dehydrate you will remove a hydroxyl group. With five oxygen atoms how can you split into two equal sized halves?
rt with.
Possible but not desirable!
H - C - OH
H - C - OH
C - OHHHHH
H - C - OH
Possible but not desirable!
Dephosphorylation of Fructose 6-phosphateeeeeee
It was a good idea to phosphorylate right at the start so for the same reasons you should leave it on.,
Possible but not desirable!
Since you have just recently put a phosphate group on carbon 6 there is much point shifting it somewhere else.
Phosphoryl Shift of Fructose 6-phosphate
Possible but not desirable!
The first stage of glycolysis involves splitting glucose into two equal halves.
If you dehydrate you will remove a hydroxyl group. With five oxygen atoms how can split into two equal sized halves?
t with.
Dehydration of Glucose 6-phosphate
Possible but not desirable!
H - C - OH
H - C - OH
C - OHHHHH
H - C - OH
The first stage of glycolysis involves splitting glucose into two equal halves.
If you dehydrate you will remove a hydroxyl group. With five oxygen atoms how can you split into two equal sized halves?
Dehydration
dose Isomerisation of
Fructose 1,6-bisphosphate
Impossible reaction!
2-Phosphoglycerate (2 moles)
Aldol
AldKet
KetAld
Dehydrate
PhosShift
DePhos
PhosOx
Oxidate
Reduce
KetAld
PhosShift
AldKet
DePhos
Dehydrate
PhosOx
Oxidate
Aldol
Reduce
Aldol
AldKet
KetAld
Dehydrate
PhosShift
DePhos
PhosOx
Oxidate
Reduce
C = OOOOOH
CH2-OH P
H - C - O - P
O- PPPPP
That dephosporylation would have a very negetive DG and would waste the opportunity to make ATP.
Go back and make some ATP.
Dephosphorylation of Phosphoenolpyruvatee
Coupled Oxidation & Phosphorylation with ATP
That gives you a massively negetive DG! The oxidation by itself has a negetive DG.
You have an oportunity to harness the energy to make a new high potential phosphate bond. Go back and use inorganic phosphate.
WOAH!!
nolpyruvate
C = OOOOOH
CH2-OH P
O- PPPPP
C - O - PPPPP
Pyruvate (2 moles)
Aldol
AldKet
KetAld
Dehydrate
PhosShift
DePhos
PhosOx
Oxidate
Reduce
KetAld
PhosShift
AldKet
DePhos
Dehydrate
PhosOx
Oxidate
Aldol
Reduce
Aldol
AldKet
KetAld
Dehydrate
PhosShift
DePhos
PhosOx
Oxidate
Reduce
C = OOOOOH
CH33OH P
O- PPPPP
C = O - PPPPP
e carbon backbone from an aldehyde or a ketone group so you would end up with a two carbon fragment and a four carbon fragment.
When you cleave your sugar you need equal sized halves.s
Aldol Cleavage of glucose
Possible but not desirable!!!
H - O - C - H
H - C - OH
H - C - OH
HC=OHH P
CH2-OH P
H - C - OH
H - C=OOOHH
H - C - OH
H - C - OH
CH2-OH P
HC=OHH P
H - C - OH
HO - C - HH
Aldol cleavage works between the carbon atom adjacent to a carbonyl group and the next carbon atom along, so you would end up with a two carbon fragment and a four carbon fragment.
When you cleave your sugar you need equal sized halves..on fragment.
When you cleave your sugar you need equal sized halves.
In the simplest form a phosphate group replaces the hydrogen of a hydroxyl group. The usual biochemical shorthand for the phosphate group is a P with a circle around it.
The DG for phosphorylation of an alcohol with inorganic phosphate is usually very positive and needs to be coupled with another process such as dephosphorylation of ATP.
H - C - HH
H - C - HH
Phosphorylation
Phosphoryl Shift
Not Possible!
Phosphoryl shift means moving a phosphate group from one part of the substrate to another.
The substrate doesn't have a phosphate group on it so this is not possible.
Dephosphorylation
Dephosphorylation means removing a phosphate group from the substrate.
The substrate doesn't have a phosphate group on it so this is not possible.
ossible.
ssible.
Impossible reaction!
Coupled Phosphorylation and Oxidation of Glucose
Possible but not desirable!
That could be done. The aldehyde group of glucose could be oxidised and phosphorylated with inorganic phosphate to capture the energy.
However, if you split glucose into two first you can do this type of reaction on both halves later and double your money!
Oxidation of Glucose
Possible but not desirable!
That's possible but not such a good idea.
At some stage you need to split your hexose into two equal halves. If you oxidise now one half will be more oxidised than the other.
Reduction of Glucose
Possible but not desirable!
That's possible but not such a good idea.
At some stage you need to split your hexose into two equal halves. If you reduce now one half will be more reduced than the other.
The DG for phosphorylation with inorganic phosphate is very positive. To make phosphorylation work you need to link it with a process with a negetive DG i.e. hydrolysis of ATP.
Go back and use ATP.
Phosphorylation with Inorganic Phosphate
Impossible
Possible but not desirable!
The first stage of glycolysis involves splitting glucose into two equal halves.
If you dehydrate you will remove a hydroxyl group and put a double bond into the carbon chain. This will make glucose less symmetrical than it was to start with.
Dehydration of Glucose 6-phosphate
Possible but not desirable!
Impossible!!
Phosphorylation of Glucose 6-phosphateeeeee
It is a good idea to phosphorylate both ends of the hexose before you split it in half. But, to keep it symmetrical you would have to phosphorylate carbon 1 which in glucose can't be phosphorylated because it is an aldehyde group.
You should swap things around to get a hydroxyl group on carbon 1 before you go ahead and phosphorylate...
Possible but not desirable!
The Task Ahead
In the transformation of glucose to lactate the hexose is split into two halves and the atoms are rearranged. The empirical formulae of glucose and lactic acid are;
So it's possible to make two moles of lactic acid from one mole of glucose with no net addition or removal of atoms.
ed than the closest monosacharide - glyceraldehyde. So you need to split glucose into two three carbon monosacharides and then rearrange.
backtrack
buttonup
buttonup
^|backtrack
startagain
buttonup
buttonup
startagain
buttonup
buttonup
continue
buttonup
buttonup
So it's possible to make two moles of lactic acid from one mole of glucose with no net addition or removal of atoms.
al formulae of glucose and lactic acid are;
So it's possible to make two moles of lactic acid from one mole of glucose with no net addition or removal of atoms.
ed than the closest monosacharide - glyceraldehyde. So you need to split glucose into two three carbon monosacharides and then rearrange.
Phosphoryl Shift
Dephosphorylation
Wingdings
:PHYSSIZE
Teaching and Learning Technology Programme
produced by the
Glycolysis Problem
Author - Jon Maberr
default
buttonUp
buttonUp
default
Start
continue
Dehydration of Glucose
The first stage of glycolysis involves splitting glucose into two equal halves.
If you dehydrate you will remove a hydroxyl group. With five oxygen atoms how can you split into two equal sized halves?ss symmetrical than it was to start with.
Possible but not desirable!
C - OHHHHH
H - C - OH
H - C - OH
H - C - OH
en rearrange.
backtrack
buttonup
buttonup
^|backtrack
startagain
buttonup
buttonup
startagain
buttonup
buttonup
continue
buttonup
buttonup
Keeping Track
You need to keep track of the amount of ATP you have made and the level of oxidation/reduction. A status area in the bottom left of the page will do this for you.
If you phosphorylate your substrate using ATP the number will decrease. If you dephosphorylate by transfering phosphate to ADP the number will increase. Oxidation/reduction is reckoned as the number of electrons removed from glucose.
When you split glucose in two you will have two moles of substrate per mole of glucose so each step will count twice.
backtrack
buttonup
buttonup
^|backtrack
startagain
buttonup
buttonup
startagain
buttonup
buttonup
continue
buttonup
buttonup
Aldol
AldKet
KetAld
Dehydrate
"What source
phosphate?"
f"&ATP"
"&Inorganic"
"Cancel"
PhosShift
DePhos
PhosOx
Oxidate
Reduce
KetAld
PhosShift
AldKet
DePhos
Dehydrate
PhosOx
Oxidate
Aldol
Reduce
Aldol
AldKet
KetAld
Dehydrate
What source of phosphate?
&Inorganic
Cancel
Inorganic
PhosShift
DePhos
PhosOx
Oxidate
Reduce
Reduce
Glucose
HO - C - HH
H - C - OH
H - C - OH
HC=OHH P
CH2-OH P
H - C - OH
Phosphorylation with Inorganic Phosphate
Impossible
The DG for phosphorylation with inorganic phosphate is very positive. To make phosphorylation work you need to link it with a process with a negetive DG i.e. hydrolysis of ATP.
Go back and use ATP..
Glucose 6-phosphate
Aldol
AldKet
KetAld
Dehydrate
PhosShift
DePhos
PhosOx
Oxidate
Reduce
KetAld
PhosShift
AldKet
DePhos
Dehydrate
PhosOx
Oxidate
Aldol
Reduce
Aldol
AldKet
KetAld
Dehydrate
PhosShift
DePhos
PhosOx
Oxidate
Reduce
HO - C - HH
H - C - OH
H - C - OH
HC=OHH P
CH2-O- P
H - C - OH
Aldol
AldKet
KetAld
Dehydrate
"What source
phosphate?"
f"&ATP"
"&Inorganic"
"Cancel"
PhosShift
DePhos
PhosOx
Oxidate
Reduce
KetAld
PhosShift
AldKet
DePhos
Dehydrate
PhosOx
Oxidate
Aldol
Reduce
Aldol
AldKet
KetAld
Dehydrate
What source of phosphate?
&Inorganic
Cancel
Inorganic
PhosShift
DePhos
PhosOx
What source of phosphate?
&Inorganic
Cancel
Inorganic
Oxidate
Reduce
Reduce
Glyceraldehyde 3-phosphate (2mol
HC = OOOOH
H - C - OH
CH2-O- P
Glyceraldehyde 3-phosphate (2 moles)
Aldol
AldKet
KetAld
Dehydrate
PhosShift
DePhos
PhosOx
Oxidate
Reduce
KetAld
PhosShift
AldKet
DePhos
Dehydrate
PhosOx
Oxidate
Aldol
Reduce
Aldol
AldKet
KetAld
Dehydrate
PhosShift
DePhos
PhosOx
Oxidate
Reduce
Fructose 1,6-bisphosphate
H - C - OH
H - C - OH
C = OOOOOH
CH2-O- P
CH2-O- P
HO - C - HH
Dihydroxyacetone Phosphate (1 mo
Dihydroxyacetone Phosphate (1 mole)
ake this into glyceraldehyde 3-phosphate.
Aldol
AldKet
KetAld
Dehydrate
PhosShift
DePhos
PhosOx
Oxidate
Reduce
KetAld
PhosShift
AldKet
DePhos
Dehydrate
PhosOx
Oxidate
Aldol
Reduce
Aldol
AldKet
KetAld
Dehydrate
PhosShift
DePhos
PhosOx
Oxidate
Reduce
CH2-O- P
C = OOOOOH
CH2-OH P
Aldol
AldKet
KetAld
Dehydrate
PhosShift
DePhos
"Where will the phosphate
Transfered
removed
%inorganic
"&Inorganic"
"Cancel"
PhosOx
Oxidate
Reduce
KetAld
PhosShift
AldKet
DePhos
Dehydrate
PhosOx
Oxidate
Aldol
Reduce
Aldol
AldKet
KetAld
Dehydrate
PhosShift
DePhos
Where will the phosphate go? Transfered to ADP or removed as inorganic phosphate.
&Inorganic
Cancel
Inorganic
PhosOx
Oxidate
Reduce
Reduce
1,3-bisphosphoglycerate
C = OOOOOH
H - C - OH
CH2-O- P
O- PPPPP
1,3-bisphosphoglycerate (2 moles)
Phosphorylation with Inorganic Phosphate
The DG for phosphorylation with inorganic phosphate is very positive. To make phosphorylation work you need to link it with a process with a highly negetive DG.drolysis of ATP.
Go back and use ATP.
Dephosphorylation of 1,3-bisphosphoglycerate
No Way!
ery very negetive DG and wou
That dephosporylation would have a very negetive DG and would waste the opportunity to make ATP.
Go back and make some ATP.rylation th
3-phosphoglycerate (2 moles)
Aldol
AldKet
KetAld
Dehydrate
PhosShift
DePhos
PhosOx
Oxidate
Reduce
KetAld
PhosShift
AldKet
DePhos
Dehydrate
PhosOx
Oxidate
Aldol
Reduce
Aldol
AldKet
KetAld
Dehydrate
PhosShift
DePhos
PhosOx
Oxidate
Reduce
C = OOOOOH
CH2-O- P
H - C - OH
O- PPPPP
Times N
ew Roman
Glucos
Times N
ew Roman
"System
Recordf
ield &name
Times N
ew Roman
Lactic
Acid
Times N
ew Roman
"System
Dihydroxyacetone is symmetrical. If you shift the phosphate group from one end to the other you still have the same molecule!
Phosphoryl Shift of Dihydroxyacetone phosphate
No Way!
C = OOOOOH
CH2-O- P
CH2-OH P
C = OOOOOH
CH2-O- P
CH2-OH P
Aldol Cleavage of Fructose 6-phosphate
That could easily be done.
You would have two three carbon sugars which is what you want. The only problem is that one product would not be phosphorylated. That might cause problems.
The next enzyme down the line will have trouble binding such a small uncharged molecule.
Possible, desirable but off the pathway!
HO - C - HHHH
H - C - O - H
H - C - OH
C=OOHH P
CH2-O- P
CH2-OH P
H - C=OOOHH
CH2-OH P
H - C - OH
CH2-O- P
C=OOHH P
c!T v
CH2-OH P
C=OOHH P
c!T v
CH2-OH P
Aldol
AldKet
KetAld
Dehydrate
"What source
phosphate?"
f"&ATP"
"&Inorganic"
"Cancel"
PhosShift
DePhos
PhosOx
Oxidate
Reduce
KetAld
PhosShift
AldKet
DePhos
Dehydrate
PhosOx
Oxidate
Aldol
Reduce
Aldol
AldKet
KetAld
Dehydrate
What source of phosphate?
&Inorganic
Cancel
Inorganic
PhosShift
DePhos
PhosOx
Oxidate
Reduce
Reduce
Fructose 6-phosphate
HO - C - HH
H - C - OH
H - C - OH
C = OOOOOH
CH2-OH P
CH2-O- P
Phosphorylation
In the simplest form a phosphate group replaces the hydrogen of a hydroxyl group. The usual biochemical shorthand for the phosphate group is a P with a circle around it.
The DG for phosphorylation of an alcohol with inorganic phosphate is usually very positive and needs to be coupled with another process such as dephosphorylation of ATP.
Aldol Cleavage of Glucose 6-phosphate
Aldol cleavage works between the carbon atom adjacent to a carbonyl group and the next carbon atom along, so you would end up with a two carbon fragment and a four carbon fragment.
When you cleave your sugar you need equal sized halves.
Possible but not desirable!
H - O - C - H
H - C - OH
H - C - OH
HC=OHH P
CH2-O- P
H - C - OH
H - C=OOOHH
H - C - OH
H - C - OH
CH2-O- P
o!$ Z 8
HC=OHH P
H - C - OH
HO - C - HH
e"Aldol &Cleavage"
e"Isomerisation (&Aldose->Ketose)"
e"De&hydration"
e"&Phosphorylation"
&Shift"
e"&Dephosphorylation"
e"Coupled P&
X && Oxidation"
e"&Reduction"
e"De&
"You must
a reaction type
the Reaction
terpage
leavepage
enterpage
continue
enterpage
Aldol &Cleavage
Isomerisation (&Aldose->Ketose)
Isomerisation (&Ketose->Aldose)
De&hydration
&Phosphorylation
Phosphoryl &Shift
&Dephosphorylation
Coupled P&hosphorylation && Oxidation
&Oxidation
&Reduction
leavepage
Aldol &Cleavage
Isomerisation (&Aldose->Ketose)
Isomerisation (&Ketose->Aldose)
De&hydration
&Phosphorylation
Phosphoryl &Shift
&Dephosphorylation
Coupled P&hosphorylation && Oxidation
&Oxidation
&Reduction
continue
You must select a reaction type from the Reaction menu.
Substrate:
startagain
buttonup
buttonup
startagain
buttonup
buttonup
backtrack
buttonup
buttonup
^|backtrack
Choose a reaction type from the Reaction menu that will get you one step nearer to lactate.
Phosphorylation
In the simplest form a phosphate group replaces the hydrogen of a hydroxyl group. The usual biochemical shorthand for the phosphate group is a P with a circle around it.
The DG for phosphorylation of an alcohol with inorganic phosphate is usually very positive and needs to be coupled with another process such as dephosphorylation of ATP.
H - C - HH
H - C - HH
buttonUp
buttonUp
Phosphoryl Shift
It is possible to remove a phosphate group from one hydroxyl group and put it on another using a single step.
In fact it is easier for the enzyme to phosphorylate to a bisphosphate and then dephosphorylate. The net result is a phosphoryl shift.
Phosphoryl shift is included here as a seperate reaction type because it can be acheived in a single step with a single enzyme.
es of glyceraldehyde 3-phosphate.....e.
Aldol
AldKet
KetAld
Dehydrate
PhosShift
DePhos
"Where will the phosphate
Transfered
removed
%inorganic
"&Inorganic"
"Cancel"
PhosOx
Oxidate
Reduce
KetAld
PhosShift
AldKet
DePhos
Dehydrate
PhosOx
Oxidate
Aldol
Reduce
Aldol
AldKet
KetAld
Dehydrate
PhosShift
DePhos
Where will the phosphate go? Transfered to ADP or removed as inorganic phosphate.
&Inorganic
Cancel
Inorganic
PhosOx
Oxidate
Reduce
Reduce
Phosphoenolpyruvate (2 moles)
C = OOOOOH
CH2-OH P
O- PPPPP
C - O - PPPPP
Fructose 6-phosphate
Good! You have moved the carbonyl group nearer the middle of the molecule so that later it can be split into two equal halves....
buttonUp
buttonUp
continue
HO - C - HH
H - C - OH
H - C - OH
C = OOOOOH
CH2-OH P
CH2-O- P
Fructose 1,6-bisphosphate
Well done. Soon you will split the carbon skeleton in two. Now that you have a phosphate at each end the products of that split will each have a phosphate 'handle'.andle'.
buttonUp
buttonUp
continue
H - C - OH
H - C - OH
C = OOOOOH
CH2-O- P
CH2-O- P
HO - C - HH
Good! Now you have 'cashed in' the phosphate bond you made in the last step and made ATP.
buttonUp
buttonUp
continue
3-phosphoglycerate (2 moles)
C = OOOOOH
CH2-O- P
H - C - OH
O- PPPPP
Shifting the phosphate was a very good idea. It will help you with the next step.e
buttonUp
buttonUp
continue
2-phosphoglycerate (2 moles)
C = OOOOOH
CH2-OH P
H - C - O - P
O- PPPPP
You have succeeded in removing a hydroxyl group from carbon 3 which gets you closer to lactate.
buttonUp
buttonUp
continue
Phosphoenolpyruvate (2 moles)
C = OOOOOH
CH2-OH P
O- PPPPP
C - O - PPPPP
Lactate (2 moles)
That's it. You've done it.
You have split glucose in two, balanced oxidation with reduction and you have made two moles of ATP per mole of glucose.
"You've completed the pathway.
Do you want
f"&Start Again"
"E&xit"
"Cancel"
startagain
"Exit"
continue
continue
You've completed the pathway. Do you want to start again or exit?
&Start Again
E&xit
Cancel
Start Again
startagain
C = OOOOOH
CH33OH P
O- PPPPP
HO - C - HPPPPP
startagain
buttonup
buttonup
startagain
buttonup
buttonup
Product(s):
Use the
button to go on to the next step in the pathway.
backtrack
buttonup
buttonup
^|backtrack
That's not a bad idea.
The isomerisation makes fructose which, unlike glucose, can be split into equal halves when subjected to aldol cleavage.
However, in glycolysis glucose is phosphorylated first. One reason for this is that it puts an irreversible step at the start of the pathway which can be a good control point. Go back and phosphorylate.
Aldose to Ketose Isomerisation of Glucose
Possible, desirable but off the pathway!!!!!
HC=OHH P
H - C - OH
C = OOOOOH
CH2-OH P
HC = OOOOH
H - C - OH
CH2-OHPPPP
HO - C - HH
CH3-OHHPPP
Fructose is not an aldose so this is not possible!
Aldose to Ketose Isomerisation of
Fructose 6-phosphateeee
Impossible!!
HC=OHH P
H - C - OH
C = OOOOOH
CH2-OH P
Fructose is not an aldose so this is not possible!
Aldose to Ketose Isomerisation of
Fructose 1,6-bisphosphate
Impossible reaction!
HC=OHH P
H - C - OH
C = OOOOOH
CH2-OH P
Dihydroxyacetone phosphate is not an aldose, it is a ketose, so this is the wrong way round.
Aldose to Ketose Isomerisation of
Dihydroxyacetone phosphate
Impossible reaction!
HC=OHH P
H - C - OH
C = OOOOOH
CH2-OH P
That is possible but it takes you further away from lactate. You need to keep the aldehyde group at one end so it can be oxidised to a carboxylic acid.
Aldose to Ketose Isomerisation of
Glyceraldehyde 3-phosphate
Possible but not desirable!
HC=OHH P
H - C - OH
C = OOOOOH
CH2-OH P
This isomerisation converts between monosacharides.
You don't have a monosacharide since you oxidised so this is not possible.
Aldose to Ketose Isomerisation of
1,3-bisphosphoglycerate
Impossible reaction!
HC=OHH P
H - C - OH
C = OOOOOH
CH2-OH P
Ketose - Aldose Isomerisation
HC=OHH P
H - C - OH
C = OOOOOH
CH2-OH P
" &&
,"",1)
Check
needs
be repositioned
be rewound (
property
This isomerisation converts between monosacharides.
You don't have a monosacharide since you oxidised so this is not possible.
Aldose to Ketose Isomerisation of
3-phosphoglycerate
Impossible reaction!
HC=OHH P
H - C - OH
C = OOOOOH
CH2-OH P
This isomerisation converts between monosacharides.
You don't have a monosacharide since you oxidised so this is not possible.
Aldose to Ketose Isomerisation of
2-phosphoglycerate
Impossible reaction!
HC=OHH P
H - C - OH
C = OOOOOH
CH2-OH P
This isomerisation converts between monosacharides.
You don't have a monosacharide since you oxidised so this is not possible.
Aldose to Ketose Isomerisation of
phosphoenolpyruvate
Impossible reaction!
HC=OHH P
H - C - OH
C = OOOOOH
CH2-OH P
This isomerisation converts between monosacharides.
You don't have a monosacharide since you oxidised so this is not possible.
Aldose to Ketose Isomerisation of
Pyruvate
lpyruvate
Impossible reaction!
HC=OHH P
H - C - OH
C = OOOOOH
CH2-OH P
Impossible reaction!
Ketose to Aldose Isomerisation of Glucose
Glucose is not a ketose so this is the wrong way round!
HC=OHH P
H - C - OH
C = OOOOOH
CH2-OH P
Glucose is not a ketose so this is not possible!
Ketose to Aldose Isomerisation of
Glucose 6-phosphate
Impossible!!
HC=OHH P
H - C - OH
C = OOOOOH
CH2-OH P
That would reverse your last step and take you back to glucose 6-phosphate so it's not a good idea
Ketose to Aldose Isomerisation of
Fructose 6-phosphate
Possible but not desirable!
HC=OHH P
H - C - OH
C = OOOOOH
CH2-OH P
You've got a phosphate group blocking carbon 1 so this can't be done. Besides which you converted to fructose for a good reason - to get the carbonyl group nearer the middle of the molecule.
Ketose to Aldose Isomerisation of
Fructose 1,6-bisphosphate
Impossible reaction!
HC=OHH P
H - C - OH
C = OOOOOH
CH2-OH P
Glyceraldehyde is an aldose, not a ketose so this can't be done.her away from lactate. You need to keep the aldehyde group at one end so it can be oxidised to a carboxylic acid.
Ketose to Aldose Isomerisation of
Glyceraldehyde 3-phosphate
Impossible reaction!
HC=OHH P
H - C - OH
C = OOOOOH
CH2-OH P
This isomerisation converts between monosacharides.
You don't have a monosacharide since you oxidised so this is not possible.
Ketose to Aldose Isomerisation of
1,3-bisphosphoglycerate
Impossible reaction!
HC=OHH P
H - C - OH
C = OOOOOH
CH2-OH P
This isomerisation converts between monosacharides.
You don't have a monosacharide since you oxidised so this is not possible.
Ketose to Aldose Isomerisation of
3-phosphoglycerate
Impossible reaction!
HC=OHH P
H - C - OH
C = OOOOOH
CH2-OH P
This isomerisation converts between monosacharides.
You don't have a monosacharide since you oxidised so this is not possible.
Ketose to Aldose Isomerisation of
2-phosphoglycerate
Impossible reaction!
HC=OHH P
H - C - OH
C = OOOOOH
CH2-OH P
This isomerisation converts between monosacharides.
You don't have a monosacharide since you oxidised so this is not possible.
Ketose to Aldose Isomerisation of
phosphoenolpyruvate
Impossible reaction!
HC=OHH P
H - C - OH
C = OOOOOH
CH2-OH P
This isomerisation converts between monosacharides.
You don't have a monosacharide since you oxidised so this is not possible.
Ketose to Aldose Isomerisation of
Pyruvate
ruvate
Impossible reaction!
HC=OHH P
H - C - OH
C = OOOOOH
CH2-OH P
That could be done. The aldehyde group could be oxidised and phosphorylated with inorganic phosphate to capture the energy.
However, if you split glucose into two first you can do this type of reaction on both halves later and double your money!!!!!!!!!!!!
Coupled Phosphorylation and Oxidation of
Glucose 6-phosphate
Possible but not desirable!
HC=OHH P
C=OOHH P
OOOOHH P
C=OOHH P
OOOOHH P
Dehydration of Glyceraldehyde 3-phosphate
Could be done but where does it lead?
The only free hydroxyl group is on carbon 2. That would be removed by a dehydration. If you remember the target is lactate which has a hydroxyl group on carbon 2 so it may not be a good idea to remove it now.
Possible but not desirable!
HC = OOOOH
H - C - OH
CH2-O- P
HC = OOOOH
H - C - OH
CH -O- P
Aldol Cleavagee
Ketose - Aldose Isomerisation
That can't be done!
Since dihydroxyacetone phosphate is a ketose there is no aldehyde group. You can't oxidise to a carboxylic acid and couple this with the formation of an acid anhydride with inorganic phosphate.
That's why you're trying to isomerise to glyceraldehyde.
your money!!
Coupled Phosphorylation and Oxidation of
Dihydroxyacetone phosphate
Impossible reaction!
C=OOHH P
OOOOHH P
C=OOHH P
OOOOHH P
C=OOHH P
You've got a phosphate group blocking carbon 1 so this can't be done. Besides which you converted to fructose for a good reason - to get the carbonyl group nearer the middle of the molecule.
Ketose to Aldose Isomerisation of
Fructose 1,6-bisphosphate
Impossible reaction!
HC=OHH P
H - C - OH
C = OOOOOH
CH2-O - P
"This
appears
)the
, will
tutorial."
f"Continue"
buttonup
buttonup
This button, when it appears at the bottom of the page, will exit you from the tutorial.
Continue
backPage
"This
appears
)the
, will take you
f"Continue"
buttonup
buttonup
This button, when it appears at the bottom of the page, will t
That can't be done!
Since you have isomerised to a ketose and there is no longer an aldehyde group you can't oxidise to a carboxylic acid and couple this with the formation of an acid anhydride with inorganic phosphate.n do this type of reaction on both halves later and double your money!!
Coupled Phosphorylation and Oxidation of
Fructose 1,6-bisphosphate
Impossible reaction!
C=OOHH P
C=OOHH P
OOOOHH P
C=OOHH P
OOOOHH P
" H n
The first stage of glycolysis involves splitting glucose into two equal halves.
If you dehydrate you will remove a hydroxyl group. With five oxygen atoms how can split into two equal sized halves?
t with.
Dehydration of Glucose 6-phosphate
Possible but not desirable!
H - C - OH
H - C - OH
C - OHHHHH
H - C - OH
The first stage of glycolysis involves splitting glucose into two equal halves.
If you dehydrate you will remove a hydroxyl group. With five oxygen atoms how can you split into two equal sized halves?
rt with.
Dehydration of Fructose 1,6-bisphosphate
Possible but not desirable!
H - C - OH
H - C - OH
C - OHHHHH
H - C - OH
Coupled Phosphorylation and Oxidation of Glucose
Possible but not desirable!
That could be done. The aldehyde group of glucose could be oxidised and phosphorylated with inorganic phosphate to capture the energy.
However, if you split glucose into two first you can do this type of reaction on both halves later and double your money!
HC=OHH P
C=OOHH P
OOOOHH P
C=OOHH P
OOOOHH P
That can't be done!
Since you have isomerised to a ketose and there is no longer an aldehyde group you can't oxidise to a carboxylic acid and couple this with the formation of an acid anhydride with inorganic phosphate.n do this type of reaction on both halves later and double your money!!
Coupled Phosphorylation and Oxidation of
Fructose 6-phosphate
Impossible reaction!
C=OOHH P
OOOOHH P
C=OOHH P
OOOOHH P
C=OOHH P
Dehydration
H - C - OH
H - C - OH
C - OHHHHH
H - C - OH
ith another process.
Phosphorylation of Glyceraldehyde 3-phosphate
Possible but not desirable!
Could be done but where does it lead? The only free hydroxyl group is on carbon 2. That would be removed by a dehydration. If you remember the target is lactate which has a hydroxyl group on carbon 2 so it may not be a good idea to remove it now.
Perhaps you should do something with the phosphates first.
Dehydration of 1,3-bisphosphoglycerateate
C = OOOOOH
H - C - OH
CH2-O- P
O- PPPPP
H - C - OH
CH -O- P
C = OOOOOH
O- PPPPP
Could be done but where does it lead? The only free hydroxyl group is on carbon 2. That would be removed by a dehydration. If you remember the target is lactate which has a hydroxyl group on carbon 2.
To get access to the hydroxyl on carbon 3 you will need to do something with the phosphate.phates first.
Dehydration of 3-phosphoglycerateeeeeeate
C = OOOOOH
H - C - OH
CH2-O- P
O- PPPPP
O- PPPPP
H - C - OH
CH -O- P
C = OOOOOH
O- PPPPP
Yes, you will need to reduce at some point. And now looks like a good time to do it. You would end up with phosphorylated lactate which you could then dephosphorylate. However, if you do it that way the two steps will each have only a moderately negetive DG and will be reversible. If you dephosphorylate the enol first the spontaneous rearrangement to pyruvate will give you a highly negetive DG and an irreversible step. That is an advantage.
Reduction of Phosphoenolpyruvateeeeee of
1,3-bisphosphoglycerateate
Possible, desirable but not optimal!!!!!
C = OOOOOH
CH2-OH P
O- PPPPP
C - O - PPPPP
C = OOOOOH
CH33OH P
O- PPPPP
H - C - O - P
Reduction of Glucose
Possible but not desirable!
That's possible but not such a good idea. Later you will cut your six carbon molecule in two using aldol cleavage.
If you reduce the aldehyde group you won't have an aldol anymore and you will have lost out on a simple method of cleavage..ride anymore and the products of cleavage won't be both monosaccharides either..
H - O - C - H
C=OOOH P
- C -- RR3
HHHHHHHHHHHHH
O = C - HHHHH
C=OOOH P
- C -- RR3
Generalised Aldol Cleaveage
Aldose - Ketose Isomerisation
HC=OHH P
H - C - OH
C = OOOOOH
CH2-OH P
An aldose is a monosaccharide with an aldehyde group. Common ketoses have a ketone group at carbon 2.
It is possible for a hydrogen atom to be moved from one carbon atom to another and so convert an aldose into a ketose.
The DG for the reaction will be near zero but there is a significant activation energy at physiological conditions which means the reaction requires an enzyme catalyst.action requires an enzyme catalyst.e both monosaccharides. The product with the blue R group must be an aldose. The other product, if a triose or larger will be a ketose.
The DG for the reaction will be near zero but there is a significant activation energy which means the reaction requires an enzyme catalyst.st
Generalised Aldol Cleaveage
c"File"
c"Edit"
c"Text"
c"Page"
c"Help"
c"&Navigation"
e"&Start Again"
e"&Continue"
e"&Backtrack"
e"E&xit"
c"&Reaction"
e"Aldol &Cleavage"
alias "
e"Isomerisation (&Aldose->Ketose)"
:AldKet"
`KetAld"
e"De&hydration"
Dehydrate"
e"&Phosphorylation"
& &Shift"
PhosShift"
e"&Dephosphorylation"
DePhos"
e"Coupled P&
&& Oxidation"
PhosOx"
Oxidate"
e"&Reduction"
Reduce"
Intro"
e"De&
key, isShift, isCtrl
sysRuntime
helpintro
"This will take you
the introductory
backtrack
Brepeatedly
.here.
Bstill want
f"&Yes"
"&No"
controls
advance through
Later
can use
these
startagain
"Are
sure
"&No"
"&No"
"Programmer ommision - couldn't carry out your
<n -
Xn -
tn -
helpintro
Aldol
AldKet
startagain
KetAld
keychar
Dehydrate
continue
PhosShift
enterbook
DePhos
PhosOx
Oxidate
backtrack
Reduce
enterbook
&Navigation
&Start Again
Navigation
&Continue
Navigation
&Backtrack
Navigation
Navigation
E&xit
Navigation
&Reaction
Aldol &Cleavage
Aldol
Reaction
Isomerisation (&Aldose->Ketose)
AldKet
Reaction
Isomerisation (&Ketose->Aldose)
KetAld
Reaction
Reaction
De&hydration
Dehydrate
Reaction
Reaction
&Phosphorylation
Reaction
Phosphoryl &Shift
PhosShift
Reaction
&Dephosphorylation
DePhos
Reaction
Reaction
Coupled P&hosphorylation && Oxidation
PhosOx
Reaction
&Oxidation
Oxidate
Reaction
&Reduction
Reduce
Reaction
&Help
&Help Intro
Aldol &Cleavage
Isomerisation (&Aldose->Ketose)
Isomerisation (&Ketose->Aldose)
De&hydration
&Phosphorylation
Phosphoryl &Shift
&Dephosphorylation
Coupled P&hosphorylation && Oxidation
&Oxidation
&Reduction
keychar
author
isCtrl
isShift
helpintro
This will take you to the introductory pages. Use the backtrack button repeatedly to get back here. Do you still want help?
Use the controls to advance through the introductory pages. Later you can use this help command to return to these pages.
&Continue
startagain
Are you sure you want to start again?
continue
buttonup
continue
Are you sure you want to exit?
backtrack
Aldol
Programmer ommision - couldn't carry out your request
AldKet
Programmer ommision - couldn't carry out your request
KetAld
Programmer ommision - couldn't carry out your request
Dehydrate
Programmer ommision - couldn't carry out your request
Programmer ommision - couldn't carry out your request
PhosShift
Programmer ommision - couldn't carry out your request
DePhos
Programmer ommision - couldn't carry out your request
PhosOx
Programmer ommision - couldn't carry out your request
Oxidate
Programmer ommision - couldn't carry out your request
Reduce
Programmer ommision - couldn't carry out your request
you still want help?
Use the controls to advance through the introductory pages. Later you can use this help command to return to these pages.
&Continue
startagain
Are you sure you want to start again?
continue
buttonup
continue
Are you sure you want to exit?
backtrack
Aldol
Programmer ommision - couldn't carry out your request
AldKet
Programmer ommision - couldn't carry out your request
KetAld
Programmer ommision - couldn't carry out your request
Dehydrate
Programmer ommision - couldn't carry out your request
Programmer ommision - couldn't carry out your request
PhosShift
Programmer ommision - couldn't carry out your request
DePhos
Programmer ommision - couldn't carry out your request
PhosOx
Programmer ommision - couldn't carry out your request
Oxidate
Programmer ommision - couldn't carry out your request
Reduce
Programmer ommision - couldn't carry out your request
Reduction of Glucose 6-phosphate
Possible but not desirable!
That's possible but not such a good idea. Later you will cut you size carbon molecule in two using aldol cleavage.
If you reduce the aldehyde group you won't have an aldol anymore and you will have lost out on a simple method of cleavage.
H - O - C - H
C=OOOH P
- C -- RR3
O = C - HHHHH
C=OOOH P
- C -- RR3
HHHHHHHHHHHHH
System
Times New Roman
Arial
Arial
h 8
Times New Roman
Times New Roman
Glycolysis Problem
Arial
Times New Roman
Wingdings
Times New Roman
Times New Roman
Times New Roman
Times New Roman
Wingdings
Times New Roman
Times New Roman
Symbol
Times New Roman
Arial
Times New Roman
Times New Roman
Times New Roman
Wingdings
Times New Roman
Wingdings
Wingdings
Arial
Times New Roman
Wingdings
Wingdings
Arial
mes New Roman
Times New Roman
Oxidation of Fructose 6-phosphate
Possible but not desirable!
That's possible but not such a good idea. Later you will cut your six carbon molecule in two using aldol cleavage.
When a monosaccharide is subjected to aldol cleavage you get two monosaccharides. If you oxidise you won't have a monosaccharide anymore and the products of cleavage won't be both monosaccharides either..
H - O - C - H
C=OOOH P
- C -- RR3
O = C - HHHHH
C=OOOH P
- C -- RR3
HHHHHHHHHHHHH
Generalised Aldol Cleaveage
0 x
0 x
Reduction of Fructose 6-phosphate
Possible but not desirable!
That's possible but not such a good idea. Later you will cut you size carbon molecule in two using aldol cleavage.
If you reduce the ketone group you won't have an aldol anymore and you will have lost out on a simple method of cleavage...
H - O - C - H
C=OOOH P
- C -- RR3
O = C - HHHHH
C=OOOH P
- C -- RR3
HHHHHHHHHHHHH
Generalised Aldol Cleaveage
4 |
4 |
Coupled Oxidation & Phosphorylation
HC=OHH P
C=OOHH P
OOOOHH P
C=OOHH P
OOOOHH P
Oxidation of an aldehyde to a carboxylic acid has a highly negetive DG even if the oxidising agent is weak.
It is possible therefore to couple the process with the formation of a phosphate group. The product is a type of
Oxidation of an aldehyde to a carboxylic acid has a highly negetive DG even if the oxidising agent is weak.
It is possible therefore to couple the process with the addition of a phosphate group. The product is a type of acid anhydride..
Oxidation of Fructose 1,6-bisphosphate
Possible but not desirable!
That's possible but not such a good idea. Later you will cut your six carbon molecule in two using aldol cleavage.
When a monosaccharide is subjected to aldol cleavage you get two monosaccharides. If you oxidise you won't have a monosaccharide anymore and the products of cleavage won't be both monosaccharides either..
H - O - C - H
C=OOOH P
- C -- RR3
O = C - HHHHH
C=OOOH P
- C -- RR3
HHHHHHHHHHHHH
Generalised Aldol Cleaveage
6 ~
6 ~
Oxidation of Glucose 6-phosphate
Possible but not desirable!
carbon molecule in two using aldol cleavage.
When a monosaccharide is subjected to aldol cleavage you get two monosaccharides. If you oxidise you won't have a monosaccharide anymore and the products of cleavage won't be both monosaccharides either.
H - O - C - H
C=OOOH P
- C -- RR3
O = C - HHHHH
C=OOOH P
- C -- RR3
HHHHHHHHHHHHH
Generalised Aldol Cleaveage
That's possible but not such a good idea. Later you will cut your six carbon molecule in two using aldol cleavage.
When a monosaccharide is subjected to aldol cleavage you get two monosaccharides. If you oxidise you won't have a monosaccharide anymore and the products of cleavage won't be both monosaccharides either..
Reduction of Fructose 1,6-bisphosphate
Possible but not desirable!
carbon molecule in two using aldol cleavage.
If you reduce the ketone group you won't have an aldol anymore and you will have lost out on a simple method of cleavage.
H - O - C - H
C=OOOH P
- C -- RR3
O = C - HHHHH
C=OOOH P
- C -- RR3
HHHHHHHHHHHHH
Generalised Aldol Cleaveage
That's possible but not such a good idea. Later you will cut your six carbon molecule in two using aldol cleavage.
If you reduce the ketone group you won't have an aldol anymore and you will have lost out on a simple method of cleavage..
Here is a list of the reaction types available to you. Click to see a one page description. Use the backtrack facility to come back here. When you are ready use the continue button to move on.
An aldose is a monosaccharide with an aldehyde group. Common ketoses have a ketone group at carbon 2.
It is possible for a hydrogen atom to be moved from one carbon atom to another and so convert a ketose into an aldose.
The DG for the reaction will be near zero but there is a significant activation energy at physiological conditions which means the reaction requires an enzyme catalyst..ction requires an enzyme catalyst.e both monosaccharides. The product with the blue R group must be an aldose. The other product, if a triose or larger will be a ketose.
The DG for the reaction will be near zero but there is a significant activation energy which means the reaction requires an enzyme catalyst.st
An aldol is an aldehyde or ketone which has a hydroxyl group attached. In the diagram the black atoms are necessary for this reaction. The R groups may be hydrogen or extended carbon skeleton.
Monosaccharides are aldols and can be subjected to this reaction. You should note that in the process one hydrogen atom is moved and a new aldehyde group is formed.
When a monosaccharide is cleaved in this way the two products are both monosaccharides. The product with the blue R group must be an aldose. The other product, if a triose or larger will be a ketose.
The DG for the reaction will be near zero but there is a significant activation energy which means the reaction requires an enzyme catalyst.st
Excellent. The hexose is split into two halves. Each half is a triose and has a phosphate group attached.
The only problem is that one half is a ketose and the other an aldose. You need to convert the mixture into two moles of glyceraldehyde 3-phosphate.....e.
Aldol Cleavagee
H - O - C - H
C=OOOH P
- C -- RR3
O = C - HHHHH
C=OOOH P
- C -- RR3
HHHHHHHHHHHHH
An aldol is an aldehyde or ketone which has a hydroxyl group attached. In the diagram the black atoms are necessary for this reaction. The R groups may be hydrogen or extended carbon skeleton.
Monosaccharides are aldols and can be subjected to this reaction. You should note that in the process one hydrogen atom is moved and a new aldehyde group is formed.
When a monosaccharide is cleaved in this way the two products are both monosaccharides. The product with the blue R group must be an aldose. The other product, if a triose or larger will be a ketose.
The DG for the reaction will be near zero but there is a significant activation energy at physiological conditions which means the reaction requires an enzyme catalyst..
Dehydration
H - C - OH
H - C - OH
C - OHHHHH
H - C - OH
Dehydration of an organic molecule is often in the form shown in the equation. An OH group is removed as a hydroxyl ion and a hydrogen attached to an adjacent atom is removed as a hydrogen ion. A double bond is formed as a result.
It is not itself a reduction despite the removal of an oxygen atom but could be a prelude to reduction which would be implemented as a hydrogenation of the double bond......
OHHHHHHHHH
HHHHHHHHHH
Phosphorylation
In the simplest form a phosphate group replaces the hydrogen of a hydroxyl group. The usual biochemical shorthand for the phosphate group is a P with a circle around it.
The DG for phosphorylation of an alcohol with inorganic phosphate is usually very positive and needs to be coupled with another process such as dephosphorylation of ATP.
O - P - OH
P - OOOOOH
P - OOOOOH
P - OOOOOH
P - OOOOOH
PPPPP - OH
R - O - P
R - O - P - P
R - O - P - P - P
R - O - P
R - O - P
R - O - P
P - OOOOOH
P - OOOOOH
buttonUp
buttonUp
backtrack
buttonup
buttonup
^|backtrack
backtrack
buttonup
buttonup
^|backtrack
Coupled Phosphorylation and Oxidation of
1,3-bisphosphoglycerateate
Off the pathway!
The first stage of glycolysis involves splitting a hexose into two equal halves.
If you dehydrate you will remove a hydroxyl group and put a double bond into the carbon chain. This will make your hexose less symmetrical than it was to start with.
Dehydration of Fructose 1,6-bisphosphate
It's already well phosphorylated. There's really no need to phosphorylate more.
(.txt)