13

Question 1

Metabolic principles:
The synthesis of ATP is exergonic / endergonic and requires energy input / releases energy.

Answer 1

Endergonic, energy input

Question 2

Metabolic principles:
What major metabolic process is coupled with production of ATP for the cell?

Answer 2

Cellular respiration

Question 3

Metabolic principles:
What are the advantages of carrying out a process in many small steps instead
of as a single reaction?

Answer 3

Each step has a small activation energy and releases a small amount of energy so more energy can be captured instead of lost as heat

Question 4

Metabolic principles:
Cellular respiration is a catabolic / anabolic pathway. Consequently, we expect that some reactions in the pathway are coupled to the production / consumption of NADH.

Answer 4

Catabolic, production

Question 5

Metabolic principles:
What are the three steps of glucose oxidation?

Answer 5

Glycolysis, pyruvate oxidation, citric acid cycle

Question 6

Metabolic principles:
When fatty acids are oxidized, how does this connect to the three steps listed above?

Answer 6

Fatty acids are converted to acetyl-CoA, which is an input to the citric acid cycle

Question 7

Electron transport details:
NADH and FADH2:

Answer 7

Electron carriers that are oxidized to provide electrons to the electron transport chain

Question 8

Electron transport details:
_________ (two functions):
1. Electron transport proteins in the inner mitochondrial membrane that are first reduced when they accept electrons, then oxidized to pass electrons to the next
molecule in the chain
2. Proton pumps that transport protons
(H+) into the intermembrane space

Answer 8

Complex I, III, IV

Question 9

Electron transport details:
O2:

Answer 9

Final electron acceptor (combines with H+ to form H2O)

Question 10

Electron transport details:
ATP Synthase (two functions):
1.
2.

Answer 10

Allows H+ to cross the inner mitochondrial membrane into the matrix, Synthesizes ATP by combining ADP and Pi

Question 11

Fermentation:
_________:
These reactions cannot occur because O2 is needed to accept electrons from NADH and FADH2 and regenerate NAD+ and FAD to accept electrons from the oxidation of glucose and fatty acids. ATP is also not produced.

Answer 11

How low O2 affects cellular respiration

Question 12

Fermentation:
When pyruvate is converted to lactate, what kind of reaction (reduction or
oxidation) occurs, and how do you know?

Answer 12

Reduction, because the carbon in
lactate has gained bonds to H.

Question 13

Fermentation:
What reaction is coupled to the pyruvate -> lactate reaction, and what is its
purpose?

Answer 13

NADH -> NAD+, this regenerates NAD+ needed for glycolysis

Question 14

__________: Fermentation allows the cell to
continue generating ATP by glycolysis. This is the only source of ATP when the other reactions of cellular respiration (especially oxidative phosphorylation) are not occurring and generating ATP.

Answer 14

Why fermentation is important when O2
is low

Question 15

Fermentation:
Why is cellular respiration important when O2 is sufficient?

Answer 15

Cellular respiration generates many more ATP per molecule of glucose than fermentation, so it is a more efficient use of glucose.