glycolysis overview

Question 1

overview

Answer 1

5-carbon sugars (glucose) and will break down in pyruvate which is two 3-C molecules

Question 2

where are enzymes found

Answer 2

enzymes found in cytosol (cytosolic), glucose is brought in via the GLUT transporter

Question 3

GLUT transporters

Answer 3

tissue specific
- GLUT 4 in muscle
- GLUT 2 is liver
- work by passive diffusion (down conc. gradient)
- a lot of glucose outside cell in liver, liver takes in some
- cell has a lot of glucose in it, must be transported out of cell (P+ glucose is kept in cell)

Question 4

Glucose potential energy

Answer 4

used to drive ATP synthesis with the reaction:
Glu + 2NAD+ + 2ADP + 2Pi –> 2 NADH + 2 pyruvate + 2ATP + 2 H2O + 4H

Question 5

under steady state conditions

Answer 5

three ways to get back NAD+ that need for glycolysis to run reaction 6 (requires NAD+)
1. aerobic oxidation (citric acid cycle, ETC ,Ox Phos)
2. Homolactic fermentation (pyruvate to lactate, anaerobic)
3. Alcoholic fermentation (ethanol)

Question 6

first step

Answer 6

HK phosphrylates position 6
- control point, operates far from eq.

Question 7

Stage 1

Answer 7

energy investment, 2 ATP invested, step 1-3

Question 8

stage 2

Answer 8

energy generated, 2 ATP/GAP = 4 overall
steps 7 and 10

Question 9

control points of glycolysis?

Answer 9

rxns 1,3,10
operate far from equilibrium (only forward direction arrows)

Question 10

strategy of glycolysis

Answer 10

1. phosphorylate glucose twice
2. convert phospho-intermediates to those that can phosphorylate ADP (delta G is greater than DGatp)
3. couple their breakdown to ATP synthesis via substrate level phosphorylation