Biology - Chapter 6: How Cells Harvest Chemical Energy; Practice Test

What is the role of the dehydrogenase enzyme at the beginning of the electron transport chain in cellular respiration?

It transfers two electrons from the glucose molecule to NAD+, reducing it to NADH.

At what point in cellular respiration is the first molecule of CO2 produced?

in the reaction that creates acetyl CoA (coenzyme A) from pyruvate

A molecule that functions as the electron donor in a redox reaction __________.

loses electrons and becomes oxidized

In cellular respiration, glucose __________ electrons and oxygen __________ electrons.

loses, gains

What process regulates the rate of cellular respiration?

feedback inhibition

A person's basal metabolic rate (BMR) is equal to about __________.

1,300-1,500 Calories/day

Each glucose molecule yields __________ molecule(s) of ATP during the citric acid cycle.

2

Each turn of the citric acid cycle generates one ATP molecule as well as which energy-rich molecules?

3 NADH and 1 FADH2

About how much ATP is produced by the metabolism of one molecule of glucose in cellular respiration?

32 molecules

Given the relatively modest number of calories burned by any but the most vigorous activities, why can most people consume more than 2,000 kilocalories per day yet maintain a healthy body weight?

A large proportion of the energy consumed in food is needed to maintain the body's functions, so only a fraction of food energy needs to be burned in exercise.

Why are wine barrels and beer fermentation vats designed to keep air out?

Facultative anaerobes prefer aerobic pathways

Which of the following statements about glycolysis is INCORRECT?

Glycolysis became a universal cellular process about the time that significant levels of O2 appeared in the atmosphere.

Which of the following statements about glycolysis is correct?

Glycolysis requires ATP to make ATP.

During fermentation, __________ that was produced during glycolysis is converted back to __________.

NADH; NAD+

Evidence suggests that heat-generating brown fat is most active in __________.

babies and lean people exposed to cold temperatures

Fueled by the ATP generated during cellular respiration, the intermediates of glycolysis and the citric acid cycle, such as pyruvate and acetyl CoA, are siphoned off and used to __________.

build proteins, fats, and carbohydrates

Glycolysis begins with __________ and ends with __________.

one molecule of glucose, two molecules of pyruvate

In oxidative phosphorylation, electrons are passed from one electron carrier to another. The energy released is used to __________.

pump protons (H+) across the mitochondrial membrane

Sunlight is essential for the varied life on Earth because it provides __________.

the energy necessary to power the rearrangement of chemical bonds in H2O and CO2

What "powers" ATP synthase, allowing it to catalyze the conversion of ADP to ATP in the presence of phosphate?

the flow of H+ ions down their concentration gradient

Oxidative phosphorylation could not occur without glycolysis and the citric acid cycle because __________.

these two stages supply the electrons needed for the electron transport chain.

Which of the following is the role of cellular respiration?

to harvest energy from organic molecules

Fat is the most efficient fuel molecule because __________.

with their numerous hydrogen atoms, fats provide an abundant source of high-energy electrons