Biology 160 - Chapter 6: Multiple Choice

The energy production per acetyl CoA molecule through the citric acid cycle is __________. 4 ATP, 8 NADH 38 ATP 1 ATP, 3 NADH, 1 FADH2 2 ATP, 6 NADH

1 ATP, 3 NADH, 1 FADH2

Consider the figure below. __________ is to a mitochondrion as __________ is to a chloroplast. O2 ... CO2 ATP ... CO2 Sunlight .... chemical energy Glucose ... O2

O2 ... CO2

Through respiration, humans breathe in O2 and breathe out CO2. However, what would happen if we did not breathe in O2? We would not have enough enzymes to catalyze reactions. We would not be able to perform lactic acid fermentation. We would not make enough ATP to meet our energy requirements We would not be able to synthesize organic molecules from inorganic molecules.

We would not make enough ATP to meet our energy requirements

Sports physiologists at an Olympic training center want to monitor athletes to determine at what point their muscles begin to function anaerobically. They could do this by checking for a buildup of _____. ATP carbon dioxide lactic acid ADP

lactic acid

In cellular respiration, glucose _____ electrons, whereas _____ electrons. loses ... oxygen gains loses ... water gains gains ... water loses gains ... oxygen loses

loses ... oxygen gains

A molecule that functions as the electron donor in a redox reaction __________. loses electrons and becomes reduced loses electrons and becomes oxidized gains electrons and becomes oxidized gains electrons and becomes reduced

loses electrons and becomes oxidized

Primarily, cellular respiration serves to _____. produce cell structures from chemical building blocks make food make ATP to power the cell's activities break down toxic molecules

make ATP to power the cell's activities

Where does glycolysis occur in a eukaryotic cell? within the intermembrane space of the mitochondrion in the mitochondria on the inner mitochondrial membrane in the cytoplasmic fluid

in the cytoplasmic fluid

A gram of fat oxidized by cellular respiration produces approximately __________ as much ATP as a gram of carbohydrate. half twice 4 times 10 times

twice

The function of cellular respiration is to _____. reduce CO2 synthesize macromolecules from monomers extract usable energy from glucose extract CO2 from the atmosphere

extract usable energy from glucose

A molecule is oxidized when it __________. loses a hydrogen ion (H+) gains a hydrogen ion (H+) gains an electron loses an electron

loses an electron

Most NADH molecules generated during cellular respiration are produced during __________. glycolysis the electron transport chain the citric acid cycle the reduction of oxygen

the citric acid cycle

Which of the following best describes the electron transport chain? Electrons pass from one carrier to another, releasing a little energy at each step. Acetyl CoA is fully oxidized to CO2. Electrons are pumped across a membrane by active transport. Hydrogens are added to CO2 to make an energy-rich compound.

Electrons pass from one carrier to another, releasing a little energy at each step.

Given the relatively modest number of calories burned by anything but the most vigorous activities, why can people consume over 2,000 kilocalories a day, yet maintain a healthy body weight? Not all calories are created equal, so a person who consumes 2,000 kilocalories of sugar- and fat-laden processed food will gain weight, whereas a person who consumes 2,000 calories of nonprocessed, low-carbohydrate food will not. They can't, and this has led to a problem of obesity in the United States. People really should exercise vigorously for one to two hours per day. Most of the energy consumed in food is spent maintaining the body's functions, so only a fraction of food energy needs to be burned in exercise.

Most of the energy consumed in food is spent maintaining the body's functions, so only a fraction of food energy needs to be burned in exercise.

What is the ultimate fate of the electrons that are stripped from glucose during cellular respiration? They are used to form ATP by chemiosmosis. They are used to form water. They are donated to NADH. They result in the formation of heat.

They are used to form water

Using the ATP generated during cellular respiration, the intermediates of glycolysis and the citric acid cycle, such as pyruvate and acetyl CoA, can be siphoned off and used to __________. create energy sources, such as glucose or amino acids, that are recycled back through respiration, thus allowing a continual source of ATP with relatively little food intake generate the ADP that is used to power biosynthetic pathways provide virtually all the heat needed to maintain body temperature build amino acids, fats, and sugars

build amino acids, fats, and sugars

In an experiment, mice were fed glucose (C6H12O6) containing a small amount of radioactive carbon. The mice were closely monitored, and in a few minutes, radioactive carbon atoms showed up in __________. water ATP heat carbon dioxide

carbon dioxide

Each turn of the citric acid cycle generates one ATP and ___ additional energy-rich molecules: __________. four; 2 NADH and 2 FADH2 four; 3 NADH and 1 FADH2 two; 1 NADH and 1 FADH2 three; 2 NADH and 1 FADH2

four; 3 NADH and 1 FADH2

In the equation shown below, during cellular respiration __________ is oxidized and __________ is reduced. glucose ... oxygen oxygen ... ATP carbon dioxide ... water ATP ... oxygen

glucose ... oxygen

During cellular respiration, glucose is oxidized. However, an intermediate __________ can be siphoned off and used to synthesize fats. pyruvate ATP glucose glyceraldehyde 3-phosphate

glyceraldehyde 3-phosphate

During glycolysis, a molecule of glucose is partially oxidized. What is the net gain of ATP and NADH for each glucose molecule during this chemical pathway? 4 ATP and 10 NADH 32 ATP and 10 NADH 2 ATP and 2 NADH 6 ATP and 10 NADH

2 ATP and 2 NADH

In the first stage of cellular respiration (glycolysis), two molecules of pyruvate are produced. In the remaining stages of cellular respiration, a number of additional products are produced, such as __________. These other stages occur in the __________. water ... cytoplasm glucose ... mitochondria ATP ... cytoplasm ATP ... mitochondria

ATP ... mitochondria

Why is the citric acid cycle called a cycle? Glucose is cycled around and resynthesized. NAD+ and FAD are recycled. NADH is recycled in the electron transport chain. Acetyl CoA binds to oxaloacetate and this compound is restored at the end of the cycle.

Acetyl CoA binds to oxaloacetate and this compound is restored at the end of the cycle.

What happens to the energy that is released by electrons as they move through the electron transport chain? It makes NADH and FADH2. It pumps H+ through a membrane. It breaks down glucose. It oxidizes water.

It pumps H+ through a membrane.

As shown below, an electron carrier, such as __________, acts as an energy-storage molecule when it is __________. NADH ... reduced NADH ... oxidized NAD+ ... oxidized NAD+ ... reduced

NADH ... reduced

A single glucose molecule produces about 38 molecules of ATP through the process of cellular respiration. However, this only represents approximately 34% of the chemical energy present in this molecule. The rest of the energy from glucose is __________. used directly for energy used to make water from hydrogen ions and oxygen converted to heat stored as fat

converted to heat

We inhale O2 and we exhale CO2. Carbon dioxide is produced __________. when oxygen acquires electrons and protons at the end of the electron transport chain during the formation of pyruvate during the electron transfer steps of oxidative phosphorylation in the reaction that creates acetyl CoA (coenzyme A) from pyruvate

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

When a car engine burns gasoline, the results of the reaction are similar to when cells burn glucose. Both reactions release carbon dioxide and water. In cells, the chemical energy in food is converted to ATP and heat. In a moving car, the chemical energy in gasoline is converted to __________. thermal energy and heat potential energy and heat kinetic energy and heat ATP and heat

kinetic energy and heat

Some human cells, such as nerve cells, are restricted to aerobic respiration to recycle NADH and FADH2. If these cells are deprived of oxygen, then __________. ATP production would continue because the cell would perform fermentation. oxidative phosphorylation would come to a halt because there wouldn't be any oxygen to "pull" the electrons down the transport chain. glycolysis could still continue indefinitely. proton gradient formation would continue, but ATP synthase function would stop.

oxidative phosphorylation would come to a halt because there wouldn't be any oxygen to "pull" the electrons down the transport chain.

In eukaryotes, most of the high-energy electrons released from glucose by cellular respiration __________. are used to form ATP by the citric acid cycle reduce NAD+ to NADH, which then delivers them to the electron transport chain are bound to FAD to be sent through the process of oxidative phosphorylation are used for synthesizing lactic acid

reduce NAD+ to NADH, which then delivers them to the electron transport chain

Glycolysis is the only stage of cellular respiration that __________. requires ATP to make ATP does not release carbon dioxide as a by-product does not require ATP to make ATP requires oxygen to function

requires ATP to make ATP

Oxidative phosphorylation could not occur without glycolysis and the citric acid cycle, because _____. these two stages provide the water that is split during oxidative phosphorylation the electron transport chain requires the ATP produced during the first two stages these two stages provide the oxygen used as the final electron acceptor these two stages supply the electrons needed for the electron transport chain

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

Fat is the most efficient molecule for long-term energy storage, even compared to carbohydrates, because _____. with their numerous hydrogen atoms, fats provide an abundant source of high-energy electrons when compacted, fat occupies less volume than an equivalent amount of carbohydrate compared to carbohydrates, fat produces fewer toxic by-products when it's metabolized fats can directly enter the electron transport chain, the phase of respiration that produces the most ATP

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