Most oxidation reactions in bacteria involve the _______.
a. removal of hydrogen ions and electrons
b. removal of oxygen
c. addition of hydrogen ions and electrons
d. addition of hydrogen ions

Which of the following reactions is an oxidation carried out by A. ferrooxidans?

a. Fe²⁺ → Fe³⁺

b. Fe³⁺ → Fe²⁺

c. CuS→ CuSO₄

d. Fe⁰ → Cu⁰

e. none of the above

Label each reactant and product in the reactions as reduced or oxidized (X is a theoretical molecule or atom).

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Use this pathway schematic to answer questions a through d.

a. Which enzyme carries out a redox reaction? In this reaction, what is being reduced and what is being oxidized?

b. Which enzyme would be the most likely to be regulated by feedback inhibition?

c. What is the end product of this pathway?

d. Which enzyme carries out substrate-level phosphorylation?

All cells require a source of ___________ for redox reactions.

Redox reactions ______.

a. transfer energy

b. transfer electrons

c. involve oxidation and reduction

d. are involved in all of the above

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.