prob_set_2glycolysis - Problem Set Glycolysis 1 A colleague...

Problem Set- Glycolysis
1. A colleague proposes to get more energy from glycolysis by engineering hexokinase to first allow the attack of
glucose on the second P of ATP and then split off one of the P
i
of the glucose pyrophosphate. Show in detail the
reaction he proposes and discuss its effect on the energetics of glycolysis.
2. Two reactions in glycolysis lead to the synthesis of ATP from ADP, and two reactions lead to the production
of ADP from ATP. One of your fellow students assumes, therefore, that the pathway balances ATP perfectly
because she feels that as much ATP is made as is used. If you agree, draw an example (including the chemical
structures of the appropriate metabolic intermediates) of a reaction that uses and an example of a reaction that
produces ATP in glycolysis. If you do not agree, explain why you disagree and describe in detail the actual ATP
and phosphate balance of glycolysis.
3. A pathway known as gluconeogenesis (converting pyruvate to glucose) progresses, in general , through
reactions similar to those of glycolysis, but in the reverse direction.
a. If you used the strict reversal of the glycolytic pathway for the reactions necessary to achieve
gluconeogenesis, diagram the single step that would produce fructose-6-phosphate from the previous
metabolic intermediate. Show the structures of all of the substrates and products involved. Also, discuss the
standard free energy change of that reaction.
b. If you were interested solely in achieving efficient gluconeogenesis, what kind of reaction would you use
instead of simply reversing the reaction that occurs in glycolysis, as above? Diagram your suggested reaction
and explain the reasoning behind your answer.