glycolysis

Question 1

what is glycolysis

Answer 1

glycolysis = initial pathway for the conversion of glucose to pyruvate

Question 2

briefly describe the 3 stages of glycolysis

Answer 2

stage 1- glucose is trapped and destabilised
stage 2- two interconvertible, 3-carbon molecules are formed
stage 3- generation of ATP

Question 3

what are the 3 control points of glycolysis

Answer 3

(all of them are enzymes that are catalysing irreversible reactions)
1- hexokinase, substrate entry
2- phosphofructokinase, rate of flow
3- pyruvate kinase, product exit

Question 4

describe the ways in which the glycolytic pathway can be controlled by activation/inhibition by different molecules

Answer 4

activators = AMP(adenosine monophosphate), increase glycolysis if energy needed
inhibitors = ATP, slows glycolysis if energy abundant
citrate, TCA cycle intermediate, slows downstream pyruvate entry to TCA cycle if energy abundant
H+, slows glycolysis if too much lactic acid produced

Question 5

what is energy charge of a cell and how does it control phosphofructokinase

Answer 5

energy charge = the ATP?AMP ratio, if cell is all ATP the cell is charged, if all AMP cell is discharged
AMP is the positive regulator

Question 6

what are the intermediate compounds of glycolysis

Answer 6

fructose-1,6-biphosphate

2 triose phosphates

Question 7

how much ATP is required for glycolysis to occur and how much is produced

Answer 7

2 ATP needed, 4 ATP produced

Question 8

what is the molecule that collects the electrons(H+) from this process and what is the fate of the electrons

Answer 8

2 NAD+ molecules bind to the 2 H+ molecules to form 2 NADH molecules which are involved in electron transport chain and ATP synthesis

Question 9

what happens if there is a lack of oxygen in the pathway, and so mitochondrial metabolism is inhibited

Answer 9

NADH is used to ferment pyruvate into lactic acid(lactate)