Glycolysis and Krebs cycle

Question 1

The first step of glycolysis results in the formation of:

Answer 1

Glucose-6-Phosphate

Question 2

Within the Krebs cycle, L-malate and NAD+ come together to form oxaloacetate, NADH and H+. What type of chemical reaction is responsible for this step in the cycle?

Answer 2

Oxidation

Question 3

For each molecule of glucose converted to pyruvate in the glycolytic pathway, ___ molecules of ATP are used initially (stage 1) and ___ molecules of ATP are produced (stage 2) for an overall yield of ___ molecules of ATP/glucose. The “ATP math” is:

Answer 3

-2 + 4 = 2

Question 4

If the Krebs cycle is overstimulated, the body will produce too much of which of the following molecules?

A. Acetyl CoA
C. Glucose
B. Carbon dioxide
D. Pyruvate

Answer 4

B. Carbon dioxide

Question 5

Which statement about glycolysis is TRUE?

A. Glycolysis cannot proceed under anaerobic conditions
B. A proton gradient is established across the mitochondrial membrane.
C. Three molecules of NADH2 and one molecule of FADH2 are produced.
D. Resulting pyruvate molecules are always directly incorporated into the Krebs cycle.

Answer 5

C. Three molecules of NADH2 and one molecule of FADH2 are produced.

Question 6

The enzyme that produces G3P and DHAP is

Answer 6

aldolase

Question 7

Before entering Krebs cycle, pyruvate is ___.

Answer 7

oxidized

Question 8

Which cell in the human body only uses glycolysis for ATP production?

a. erythrocyte
c. myocyte
b. hepatocyte
d. neuron

Answer 8

a. erythrocyte

Question 9

How are electrons extracted from the citric acid cycle for use in the electron transport chain?

Answer 9

oxidation of NAD+ and FAD

Question 10

Which of the following biological processes will occur under both aerobic and anaerobic conditions in human?

a. citric acid cycle
c. glycolysis
b. fermentation
d. Krebs cycle

Answer 10

c. glycolysis