Glycolysis

Question 1

What enzyme catalyzes the first step of glycolysis in non-liver cells?

Answer 1

Hexokinase

Question 2

What is the functional purpose of glucokinase?

Answer 2

It attaches a phosphate to glucose in order to trap them within the cell

Question 3

What enzyme catalyzes the first step of glycolysis in liver cells

Answer 3

Glucokinase

Question 4

What is the second step of glycolysis, and what enzyme catalyzes it?

Answer 4

1: Glucose-6-phosphate –> Fructose-6-phosphate

#2: Phosphoglucose Isomerase

Question 5

What is the third step of glycolysis? What enzyme catalyzes it?

Answer 5

1: Fructose-6-phosphate + ATP –> Fructose 1,6 Bisphosphate + ADP

#2: Phosphofructokinase

Question 6

What is the fourth step of glycolysis?

Answer 6

Fructose 1,6 Bisphosphate –> Dihydroxyacetone Phosphate + Glyceraldehyde-3-phosphate

Question 7

What is the first step of glycolysis?

Answer 7

Glucose + ATP –> Glucose-6-phosphate + ADP

Question 8

What is the fifth step of glycolysis? What enzyme catalyzes it?

Answer 8

1: Dihydroxyacetone Phosphate –> Glyceraldehyde-3-phosphate.

#2: Triose Phosphate Isomerase

Question 9

What is the first step in glycolysis that generates NADH?

Answer 9

Step #6: 2x Glyceraldehyde-3-phosphate + 2 NAD+ –> 2x 1,3 Bisphosphoglycerate + 2 NADH

Question 10

What is happening in Step #6 in glycolysis? What enzyme catalyzes it?

Answer 10

1: Each of the 3 carbon intermediates is oxidized whilst NAD+ is reduced in a redox reaction. Excess energy is used to phosphorylate the 3 carbon intermediate.

#2: Glyceraldehyde-3-phosphate Dehydrogenase.

Question 11

Which of the following best explains what occurs in step #7 of glycolysis?

W) Dehydrogenase oxidizes 1,3 Bisphosphoglycerate and reduces NAD+
X) Dehydrogenase oxidizes NADH and reduces 1,3 Bisphosphoglycerate
Y) Kinase catalyzes the transfer of a phosphate group from 1,3 Bisphosphoglycerate to ADP
Z) Kinase catalyzes the transfer of a phosphate group from ATP to 1,3 Bisphosphoglycerate

Answer 11

Y) Kinase catalyzes the transfer of a phosphate group from 1,3 Bisphosphoglycerate to ADP

Question 12

What enzyme catalyzes the seventh step of glycolysis?

Answer 12

Phosphoglycerate Kinase

Question 13

What intermediate is (?) in the reaction: 1,3 Bisphosphoglycerate + ADP –> (?) + ATP

Answer 13

3-Phosphoglycerate

Question 14

Describe what occurs in the 8th step of glycolysis using words.

Answer 14

The phosphate is transferred from the 3rd carbon to the 2nd carbon in an rearrangement reaction, no energy is released or spent.

Question 15

Describe the chemical reaction of the 8th step of glycolysis, and name the enzyme responsible.

Answer 15

1: 3-Phosphoglycerate –> 2-Phosphoglycerate

#2: Phosphoglycerate Mutase

Question 16

Describe the 9th step of glycolysis using words

Answer 16

Detatchment of an -OH and H attached to the carbon to create a high energy molecule (and generates H2O)

Question 17

Describe the chemical reaction of the 9th step of glycolysis, and name the enzyme responsible.

Answer 17

1: 2-Phosphoglycerate –> Phosphoenolpyruvate (PEP) + H2O

#2: Enolase

Question 18

Describe the chemical reaction of the 10th step of glycolysis, and name the enzyme responsible.

Answer 18

1: PEP + ADP –> Pyruvate + ATP

#2: Pyruvate Kinase

Question 19

What is the final yield of products for glycolysis from one molecule of glucose? [not net]

Answer 19

2x Pyruvate, 2x NADH, 4x ATP

Question 20

Indicate all of the following enzymes that generate ATP via substrate-level phosphorylation:
1) Phosphofructokinase
2) Hexokinase
3) Glyceraldehyde-3-phosphate Dehydrogenase
4) Pyruvate Kinase

Answer 20

3 and 4

Question 21

Which enzyme is the rate-limiting enzyme of glucose?

Answer 21

Phosphofructokinase

Question 22

Where does glycolysis take place in the cell?

Answer 22

Cytosol