NADH is commonly used as an electron carrier during the breaking down of complex molecules like glucose in cellular respiration. NADPH is also a common electron carrier. However, NADPH is used to build complex molecules like glucose in a process called:

A reduced molecule ______.

a. has gained electrons

b. has become more positive in charge

c. has lost electrons

d. is an electron donor

Oxidation is the _________________________, and reduction is the _________________________.

a) Gain of electrons; Loss of electrons.

b) Gain of protons; Loss of protons. 

c)  Loss of electrons; Gain of electrons.

d)  Gain of oxygen; Loss of oxygen.

When glucose donates electrons to NAD⁺ creating NADH, the glucose molecule becomes:

a) Hydrolyzed.

b) Oxidized.

c) Neutral.

d) Reduced.

An electron carrier before it harvests energy from glucose molecules in a series of gradual steps is:

a) Pyruvate.

b) AMP.

c) ATP.

d) NAD⁺.

e) NADH.

Which electron carrier is not matched with its correct function.

Define oxidation-reduction, and differentiate the following terms:

a. aerobic and anaerobic respiration

b. respiration and fermentation

c. cyclic and noncyclic photophosphorylation

Why must NADH be reoxidized? How does this happen in an organism that uses respiration? Fermentation?

Which substance in the following reaction is being reduced?

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a. acetaldehyde

b. NADH

c. ethanol

d. NAD⁺