BackOxidation 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.
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:
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⁺
In the sulfur cycle, microbes degrade organic sulfur compounds, such as (a) _________________, to release H₂S, which can be oxidized by Acidithiobacillus to (b) _________________. This ion can be assimilated into amino acids by (c) _________________ or reduced by Desulfovibrio to (d) _________________. H₂S is used by photoautotrophic bacteria as an electron donor to synthesize (e) _________________. The sulfur-containing by-product of this metabolism is (f) _________________.
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.
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
Redox reactions ______.
a. transfer energy
b. transfer electrons
c. involve oxidation and reduction
d. are involved in all of the above