Question

Glycolysis

a) occurs in the liver during arduous exercise

b) has a net energy gain

c) provides a storage form of glucose

d) costs 4 ATP + 2 GTP per glucose synthesized

Stage 1 of glycolysis includes steps 1-3. These reaction types include

a) isomerization, phosphorylation

b) isomerization, dehydrogenation

c) cleavage, dehydrogenation

d) dehydration, phosphorylation

Which step of glycolysis generates ATP?

a) Step 4, cleavage of F-1,6-BP (fructose-1,6-bisphosphate) to DHAP

(dihydroxyacetonephosphate) plus GAP (glyceraldehyde-3-phosphate)

b) Step 5, isomerization of DHAP to GAP

c) Step 6, oxidation of GAP to 1,3-bisphosphoglycerate

d) Step 10, conversion of PEP (phosphenolpyruvate) to pyruvate

Resting muscle tightly regulates the enzyme PFK (phosphofructokinase)

a) because it catalyzes the only step in glycolysis with a significant energy release

b) through feedback inhibition by ATP

c) through feedback stimulation by NADH

d) independently of its enzyme activity

Answer 1

1) b net energy gain.

During glycolysis total 6 ATP produce and out of 6 two ATP are consumed in the first two step of glycolysis.

So, net four ATP produce which result in energy gain.

2) a isomerisation and phosphorylation

In first step : glucose is converted to glucose 6 phosphate by phosphorylation.( Hexokinase)

In second step: glucose 6 phosphate is converted to fructose 6 phosphate by isomerisation .( Phosphoglucoisomerase).

In third step: fructose 6 phosphate is converted to fructose 1,6 bisphosphate by phosphorylation .( Phosphofructokinase).

3) d conversion of pep to pyruvate.

In this step substrate level phosphorylation occur and phosphoenolpyruvate is converted to pyruvate.( Pyruvate kinase).

4) b through feedback inhibition by ATP.

Phosphofructokinase catalyse the reaction where fructose 6 phosphate is converted to fructose 1,6 bisphosphate. This is the irreversible step and the enzyme can be inhibited by ATP and citrate.