Test 3: Glycolysis Flashcards
What is glycolysis?
- first metabolic pathway
- metabolises 1 molecule of glucose into 2 molecules of puruvate
- produces 8 ATP
- anaerobic process
What is the first metabolic pathway?
glycolysis
What are the products and reactants of Glycolysis?
reactant: 1 glucose
product: 2 pyruvate + 8ATP
How many molecules of ATP does glycolysis yield?
8 molecules of ATP
Is glycolysis aerobic or anaerobic?
anaerobic
What can happen after glycolysis to the pyruvate molecules? (with and without oxygen presence)
anaerobically:
pyruvate is fermented into lactate or ethanol and CO2
aerobically:
pyruvate is completely oxidised to carbon dioxide, generating more ATP
State the anaerobic reactions of pyruvate.
2pyruvate –> 2ethanol + 2CO2
2pyruvate –> 2lactate
State the aerobic reactions of pyruvate.
2pyruvate –> 2acetyl-CoA –> 4CO2 + 4H2O
How many enzyme catalysed reactions are there in glycolysis? How many stages are they divided into? What is the stage-division based on?
10 enzyme catalysed reactions
2 stages
STAGE 1 (preparatory phase):
- glucose –> 2G3P
- (loss of 2 ATP)
STAGE 2 (payoff phase):
- 2G3P –> 2pyruvate
- (gain 4 ATP and 2 NADH)
What are the major steps of stage 1?
1) phosphorylation of glucose –> glucose 6-phosphate
2) isomerization of G6P –> fructose 6-phosphate
3) transpher of phosphoryl group from ATP to C’1 –> fructose 1,6-bisphosphate
4) cleavage of fructose 1,6-bisphosphate –> glyceraldehyde 3 phosphate (aldose) + dihydroxy acetone phosphate (ketose)
5) triose phosphate mutose reaction: dihydroxy acetone phosphate (ketose) –> glyceraldehyde 3 phosphate (aldose)
What catalyses step 1?
glucose hexokinase
What catalyses step 2?
- phosphohexose isomerase
- Mg2+
What catalyses step 3?
- phosphofructokinase
- Mg2+
(ATP –> ADP + Pi)
What catalyses step 4?
aldolase
What catalyses step 5?
triose phosphate isomerase