Concepts of Biology

Samantha Fowler, Rebecca Roush, James Wise

Chapter 4

How Cells Obtain Energy - all with Video Answers

Educators

KS

Chapter Questions

Problem 1

Figure 4.6 Look at each of the processes shown and decide if it is endergonic or exergonic.

Joanna Quigley

Joanna Quigley

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Problem 2

Figure 4.15 Cyanide inhibits cytochrome $c$ oxidase, a component of the electron transport chain. If cyanide poisoning occurs, would you expect the pH of the intermembrane space to increase or decrease? What affect would cyanide have on ATP synthesis?

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Problem 3

Figure 4.16 Tremetol, a metabolic poison found in white snake root plant, prevents the metabolism of lactate. When cows eat this plant, Tremetol is concentrated in the milk. Humans who consume the milk become ill. Symptoms of this disease, which include vomiting, abdominal pain, and tremors, become worse after exercise. Why do you think this is the case?

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Problem 4

Which of the following is not an example of an energy transformation?
a. Heating up dinner in a microwave
b. Solar panels at work
c. Formation of static electricity
d. None of the above

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Numerade Educator

Problem 5

Which of the following is not true about enzymes?
a. They are consumed by the reactions they catalyze.
b. They are usually made of amino acids.
c. They lower the activation energy of chemical reactions.
d. Each one is specific to the particular substrate(s) to which it binds.

Carlene Jimenez

Carlene Jimenez

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Problem 6

Energy is stored long-term in the bonds of _____ and used short-term to perform work from
a(n) _____ molecule.
a. ATP: glucose
b. an anabolic molecule : catabolic molecule
c. glucose : ATP
d. a catabolic molecule : anabolic molecule

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Problem 7

The glucose that enters the glycolysis pathway is split into two molecules of _________.
a. ATP
b. phosphate
c. NADH
d. pyruvate

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Problem 8

The energy currency used by cells is _____.
a. ATP
b. ADP
c. AMP
d. adenosine

KS

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Problem 9

What do the electrons added to $\mathrm{NAD}^{+}$ do?
a. They become part of a fermentation pathway.
b. They go to another pathway for ATP production.
c. They energize the entry of the acetyl group into the citric acid cycle.
d. They are converted into NADP.

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Problem 10

Chemiosmosis involves
a. the movement of electrons across the cell membrane
b. the movement of hydrogen atoms across a mitochondrial membrane
c. the movement of hydrogen ions across a mitochondrial membrane
d. the movement of glucose through the cell membrane

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Problem 11

Which of the following fermentation methods can occur in animal skeletal muscles?
a. lactic acid fermentation
b. alcohol fermentation
c. mixed acid fermentation
d. propionic fermentation

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Problem 12

The cholesterol synthesized by cells uses which component of the glycolytic pathway as a
starting point?
a. glucose
b. acetyl CoA
c. pyruvate
d. carbon dioxide

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Numerade Educator

Problem 13

Beta oxidation is ________.
a. the breakdown of sugars
b. the assembly of sugars
c. the breakdown of fatty acids
d. the removal of amino groups from
amino acids

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Numerade Educator

Problem 14

Does physical exercise to increase muscle mass involve anabolic and/or catabolic processes?
Give evidence for your answer

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Problem 15

Explain in your own terms the difference between a spontaneous reaction and one that
occurs instantaneously, and what causes this difference.

Joanna Quigley

Numerade Educator

Problem 16

With regard to enzymes, why are vitamins and minerals necessary for good health? Give
examples.

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Numerade Educator

Problem 17

Both prokaryotic and eukaryotic organisms carry out some form of glycolysis. How does that
fact support or not support the assertion that glycolysis is one of the oldest metabolic
pathways?

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Problem 18

We inhale oxygen when we breathe and exhale carbon dioxide. What is the oxygen used
for and where does the carbon dioxide come from?

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Problem 19

When muscle cells run out of oxygen, what happens to the potential for energy extraction from
sugars and what pathways do the cell use?

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Numerade Educator

Problem 20

Would you describe metabolic pathways as inherently wasteful or inherently economical, and
why?

Joanna Quigley

Numerade Educator