Chapter 21: Carbohydrate Metabolism Quiz

What polymer is the principal storage form of glucose?

Glycogen

Why is the pentose phosphate pathway important?

It is an alternate pathway for glucose oxidation, and provides important molecules such as NADPH and sugar phosphates

Which enzyme catalyzes the hydrolysis of milk sugar?

Lactase

Which coenzyme form must be reoxidized so that glycolysis can continue to produce ATP for the cell?

NADH

What is the first reaction in glycolysis, which traps glucose within the cell?

Phosphorylation of glucose

What is meant by the term catabolism?

The degradation (breakdown) of molecules with an accompanying release of energy

How many NADH are produced for each glucose molecule that enters glycolysis?

2

At the end of glycolysis, how many pyruvate molecules have been produced from 10 glucose molecules?

20

Approximately how much energy, in kilocalories, is released by one mole of ATP in the hydrolysis reaction shown below? ATP + water → ADP + Pi + energy

7

Digestion of carbohydrates begins in the mouth with the aid of what enzyme?

Amylase

Aldolase splits fructose-1,6-bisphosphate into two compounds. One is glyceraldehyde-3-phosphate. What is the other product of this reaction?

Dihydroxyacetone phosphate

The hormone insulin stimulates which of the following biochemical pathways?

Glycogenesis

The hormones glucagon and epinephrine primarily control which biochemical pathway?

Glycogenolysis

When one molecule of glucose undergoes glycolysis followed by lactate fermentation, what happens to the net number of NAD+ and NADH molecules?

There is no net change in the number of molecules of either NAD+ or NADH

What is the function of coenzyme A?

To carry acetyl groups in the form of acetyl CoA to the citric acid cycle

Glycogenesis occurs under which of the following conditions?

When digestion of polysaccharides provides high levels of blood glucose