BIOL 1030 Chapter 6 Homework Questions

The transfer of ___ from one molecule to another is an oxidation-reduction reaction, or redox reaction.

electrons

Each turn of the citric acid cycle generates one ATP and ___ additional energy-rich molecules: __________. View Available Hint(s) two; 1 NADH and 1 FADH2 four; 3 NADH and 1 FADH2 four; 2 NADH and 2 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. carbon dioxide ... water ATP ... oxygen oxygen ... ATP glucose ... oxygen

glucose ... oxygen

A chemist has discovered a drug that blocks phosphoglucoisomerase, an enzyme that catalyzes the second reaction in glycolysis. He wants to use the drug to treat people with bacterial infections. However, he can't do this because _____. A) bacteria are facultative anaerobes; they usually don't need to perform glycolysis B) bacteria do not perform glycolysis C) glycolysis produces so little ATP that the drug will have little effect D) human cells also perform glycolysis; the drug might also poison them

human cells also perform glycolysis; the drug might also poison them

A scientist wants to study the enzymes of the citric acid cycle in eukaryotic cells. What part of the cell would she use as a source of these enzymes? plasma membrane mitochondrial matrix cytoplasm mitochondrial inner membrane

mitochondrial matrix

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

the citric acid cycle

For each glucose that enters glycolysis, _____ NADH enter the electron transport chain. 6 2 4 10 0

10

How many NADH are produced by glycolysis? 5 1 2 3 4

2

In glycolysis there is a net gain of _____ ATP. 1 2 5 4 3

2

Which of these is NOT a product of glycolysis? NADH + H+ FADH2 water ATP pyruvate

FADH2

Which of these enters the citric acid cycle (also called the Krebs cycle)? G3P pyruvate glucose acetyl CoA NADH + H+

acetyl CoA

Through respiration, humans breathe in O2 and breathe out CO2. However, what would happen if we did not breathe in O2? We would not be able to perform lactic acid fermentation. We would not have enough enzymes to catalyze reactions. 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

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 __________. A) ATP production would continue because the cell would perform fermentation B) glycolysis could still continue indefinitely C) oxidative phosphorylation would come to a halt because there wouldn't be any oxygen to "pull" the electrons down the transport chain D) 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

The final electron acceptor of cellular respiration is _____. CO2 FADH2 oxygen water NADH

oxygen

NADH delivers electrons to an electron transport chain, which passes the electrons through carrier molecules in a series of redox reactions to the final electron acceptor, ___

oxygen.

Bacteria have no membrane-enclosed organelles. However, some still generate ATP through cellular respiration. Where might the electron transport chain be found in these organisms? View Available Hint(s) nucleoid region plasma membrane mitochondria cytoplasm

plasma membrane

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

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

. In cellular respiration, oxygen becomes ___ to water (H2O) as it gains electrons (in hydrogen atoms) that came from glucose

reduced

In glycolysis, ATP molecules are produced by _____. photophosphorylation photosynthesis oxidative phosphorylation cellular respiration substrate-level phosphorylation

substrate-level phosphorylation

In the citric acid cycle (also called the Krebs cycle), ATP molecules are produced by _____. oxidative phosphorylation cellular respiration substrate-level phosphorylation photosynthesis photophosphorylation

substrate-level phosphorylation

In glycolysis, what starts the process of glucose breakdown? Pyruvate FADH2 ATP ADP NADPH

ATP

The energy released from the redox reactions in the electron transport chain is used by the cell to make ___

ATP

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

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

Which of the following statements regarding glycolysis is FALSE? Glycolysis plays a role in both fermentation and respiration. Glycolysis evolved in an oxygen-rich environment. Glycolysis does not require compartmentalization by internal membranes. Glycolysis is the most widespread metabolic pathway found in Earth's life.

Glycolysis evolved in an oxygen-rich environment.

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

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

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? A) People really should exercise vigorously for one to two hours per day. B) They can't, and this has led to a problem of obesity in the United States. C) 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. D) 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.

In cellular respiration, organic molecules become oxidized as ____picks up electrons and H+ and becomes reduced to NADH.

NAD+

During electron transport, energy from _____ is used to pump hydrogen ions into the _____. NADH and FADH2 ... mitochondrial matrix NADH and FADH2 ... intermembrane space acetyl CoA ... intermembrane space NADH ... mitochondrial matrix NADH ... intermembrane space

NADH and FADH2 ... intermembrane space

Which of these is NOT a product of the citric acid cycle (also called the Krebs cycle)? NADH + H+ CO2 FADH2 acetyl CoA ATP

acetyl CoA

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 carbon dioxide heat ATP

carbon dioxide

The O2 required for __________ is supplied by _______ breathing ... cellular respiration CO2 ... cellular respiration cellular respiration ... breathing cellular respiration ... ATP

cellular respiration ... breathing

In nutrient-rich environments (like your mouth), bacteria can use the provided amino acids to synthesize their proteins. However, should the environmental conditions change and become nutrient-poor, bacteria would need to synthesize their amino acids. They can do this using __________. glucose glyceraldehyde 3-phosphate ATP citric acid cycle intermediates

citric acid cycle intermediates

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 to make water from hydrogen ions and oxygen stored as fat converted to heat used directly for energy

converted to heat

The proximate (immediate) source of energy for oxidative phosphorylation is _____. A) NADH and FADH2 B) ATP synthase C) substrate-level phosphorylation D) kinetic energy that is released as hydrogen ions diffuse down their concentration gradient E) ATP

kinetic energy that is released as hydrogen ions diffuse down their concentration gradient

In muscle cells, fermentation produces _____. lactate and NAD+ carbon dioxide, ethanol, NAD+, and ATP pyruvate lactate and NADH carbon dioxide, ethanol, NADH, and ATP

lactate and NAD+

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 _____. lactic acid ATP ADP carbon dioxide

lactic acid

In cellular respiration, most ATP molecules are produced by _____. photosynthesis photophosphorylation cellular respiration substrate-level phosphorylation oxidative phosphorylation

oxidative phosphorylation

. In cellular respiration, glucose becomes ___ to carbon dioxide (CO2) as it loses electrons (in hydrogen atoms).

oxidized

A gram of fat oxidized by cellular respiration produces approximately __________ as much ATP as a gram of carbohydrate. View Available Hint(s) half twice 4 times 10 times

twice