Chapter 7: Biology Learning Curve and Quiz

True of False: During the action of ATP synthase, the kinetic energy of the proton gradient is transformed into potential energy.

False

True of False: Fermentation produces nearly two times as much ATP as aerobic respiration, which explains why it is a preferred pathway for bacteria.

False

True of False: Malate is both the starting and ending product of the citric acid cycle.

False

True of False: Pyruvate oxidation is remarkably similar to glycolysis in that when one molecule of pyruvate enters into a mitochondrion, two molecules of acetyl-CoA are formed.

False

Which of the following does not occur during the third phase of glycolysis? None of the other answer options is correct. the transfer of high-energy electrons to NAD+ ATP synthesis pyruvate production oxygen consumption

oxygen consumption

True of False: The majority of cells within the human body have a very high baseline amount of ATP, so cells are always prepared for any long-term activity.

False

How many reactions in glycolysis directly generate ATP?

2

The enzyme phosphofructokinase-1 (PFK-1) is thought of as a metabolic "valve" that regulates the rate of glycolysis. Which of the following correctly identifies its allosteric activators and inhibitors and their actions? ADP—activator; ATP—activator ADP—activator; citrate—inhibitor CoQ—activator; citrate—inhibitor ATP—activator; AMP—inhibitor AMP—activator; CoQ—inhibitor

ADP—activator; citrate—inhibitor

Recall that fatty acids (like palmitic acid) can yield substantially more ATP when compared with glucose. Why doesn't aerobic respiration rely solely on fatty acids as energy sources, rather than glucose?

Fatty acids cannot be used by some vital tissues in the human body, such as the brain.

You may be familiar with the story of Philippides, the famous Greek runner who ran the first marathon and then died after completing his run. Based on what you know of aerobic respiration and fermentation, why might Philippides have died? His muscles may have produced toxic levels of ethanol, causing his blood to become more acidic. His muscles may have produced toxic levels of ethanol, causing his blood to become more basic. His muscles may have produced toxic levels of both ethanol and lactic acid, causing his blood to become more acidic. His muscles may have produced toxic levels of lactic acid, causing his blood to become more acidic. His muscles may have produced toxic levels of lactic acid, causing his blood to become more basic.

His muscles may have produced toxic levels of lactic acid, causing his blood to become more acidic.

In what organelle is pyruvate oxidation carried out in a cell? endoplasmic reticulum Golgi apparatus chloroplast mitochondrion nucleus

Mitochondrion

When a single pyruvate is converted to acetyl-CoA, the other products of the reaction are:

NADH and CO2.

During what stage is the most ATP produced during cellular respiration?

Oxidative Phosphorylation

Which of the following statements is true regarding pyruvate oxidation? Pyruvate oxidation forms the same number of NADH (per glucose molecule) as glycolysis. Like glycolysis, pyruvate oxidation is carried out in the mitochondria. Pyruvate oxidation ends with the oxidation of an acetyl group, which forms CO2. Pyruvate oxidation directly follows the citric acid cycle during cellular respiration.

Pyruvate oxidation forms the same number of NADH (per glucose molecule) as glycolysis.

Which is the only reaction in the citric acid cycle that produces ATP by substrate-level phosphorylation? the formation of succinate the formation of oxaloacetate the formation of fumarate the formation of malate the formation of citrate

The formation of succinate

Which of the following statements is true regarding the equation C6H12O6 + 6O2 →6CO2+ 6H2O + energy? The oxygen atoms in both CO2 and H2O are electronegative, and glucose is considered a reducing agent. The movement of hydrogen atoms in reactions involving C6H12O6 and H2O yields no information regarding the movement of electrons. The oxygen atoms in both CO2 and H2O are electronegative. In the production of CO2 from glucose, the oxygen atoms lose electrons and the carbon atom is oxidized. Glucose could be considered a reducing agent.

The oxygen atoms in both CO2 and H2O are electronegative, and glucose is considered a reducing agent.

A researcher is studying a population of bacteria that carry out the citric acid cycle, but do so in reverse. What statements are likely true of these bacteria? These bacteria carry out cellular respiration in their mitochondria. These bacteria will release CO2 as a waste product and will carry out cellular respiration within their mitochondria. An individual bacterium will produce most of its energy by means of the citric acid cycle. These bacteria will release CO2 as a waste product. These bacteria will produce sugars from intermediates of the citric acid cycle.

These bacteria will produce sugars from intermediates of the citric acid cycle.

Which of the following statements is true regarding triacylglycerols? Triacylglycerols are stored in the liver and are used to produce ATP via substrate-level phosphorylation. Triacylglycerols can be used to generate acetyl-CoA. ATP is derived from triacylglycerols through beta-oxidation and substrate-level phosphorylation. Triacylglycerols have no structural similarities to glycerol. Like glycogen, triacylglycerols are stored primarily in the liver.

Triacylglycerols can be used to generate acetyl-CoA.

True of Face: Although glycolysis produces four molecules of ATP by substrate-level phosphorylation, the net gain of ATP for the cell is two molecules. This is due to the fact that glycolysis is—at first—endergonic.

True

True of False: The ATP produced during glycolysis is the result of substrate-level phosphorylation.

True

Energy released by transferring electrons along the electron transport chain is stored as potential energy in the form of: ATP synthase. coenzyme Q . a proton gradient. ATP. redox couples.

a protein gradient

Is glycolysis aerobic or anaerobic?

anaerobic (does not require oxygen)

Phosphorylating glucose during phase 1 of glycolysis: releases phosphorylated glucose from cells. destabilizes the glucose molecule so that it can be broken down in phase 2. provides electrons to reduce NAD+ in phase 3. provides electrons to reduce FADH in phase 3. None of the other answer options is correct.

destabilizes the glucose molecule so that it can be broken down in phase 2.

In the first three stages of cellular respiration, the chemical energy in glucose is transferred to: only coenzyme Q. cytochrome b and coenzyme Q. proton pumps and ATP. electron carriers and ATP. ATP and cytochrome b.

electron carriers and ATP.

The proteins of the electron transport chain are: located in the mitochondrial matrix. embedded in both mitochondrial membranes. located in the intermembrane space of mitochondria. embedded in the outer mitochondrial membrane. embedded in the inner mitochondrial membrane.

embedded in the inner mitochondrial membrane.

In cellular respiration, oxygen:

gains electrons and is an oxidizing agent.

In which form are electrons transferred during typical redox reactions such as the oxidation of glucose? as hydrogen atoms as free electrons as oxygen atoms as carbon atoms as phosphate groups

hydrogen atoms

Fermentation takes place: in the mitochondrial matrix. in the intermembrane space of mitochondria. on the outer mitochondrial membrane. on the inner mitochondrial membrane. in the cytoplasm.

in the cytoplasm

PFK-1 is _____ by ATP and _____ by ADP. activated; activated activated; inhibited inhibited; inhibited inhibited; activated

inhibited; activated

Which of the following statements is true regarding a reducing agent? It is usually oxygen. It is an electron acceptor. It is never oxidized. It loses electrons. It gains electrons.

it loses electrons

Starting with glycolysis, lactic acid and ethanol fermentation generate only two ATP molecules per glucose molecule. The remaining chemical energy from the glucose is found primarily in: lactic acid and ethanol. CO2. FADH2. NADH. GTP.

lactic acid and ethanol

The chemical bonds of carbohydrates and lipids have high potential energy because: they are strong reducing agents. they are easy to phosphorylate. they are easy to hydrolyze. many of these bonds are C—C and C—H bonds. they are strong oxidizing agents.

many of these bonds are C—C and C—H bonds.

The citric acid cycle begins when acetyl-CoA combines with _____ to form _____. pyruvate; citrate oxaloacetate; citrate malate; oxaloacetate oxaloacetate; malate citrate; cis-aconitate

oxaloacetate; citrate

During the citric acid cycle, the production of CO2 is the result of the _____ of intermediate compounds of the citric acid cycle coupled to the production of _____.

oxidation; Naph

The electron transport chain is part of: pyruvate oxidation. oxidative phosphorylation. glycolysis. fermentation. the citric acid cycle.

oxidative phosphorylation

In cellular respiration, glucose is _____ to CO2 and oxygen is _____ to water.

oxidized; reduced

When an electron is transferred from NADH to CoQ, NADH is _____ and CoQ is _____.

oxidized; reduced

The final electron acceptor of the electron transport chain is:

oxygen

In the second phase of glycolysis: Please choose the correct answer from the following choices, and then select the submit answer button. ATP is generated by oxidative phosphorylation. phosphate groups are added to glucose. ATP is generated by substrate-level phosphorylation. NAD+ is reduced to NADH. phosphorylated sugar molecule is cleaved and the products rearranged.

phosphorylated sugar molecule is cleaved and the products rearranged.

In which organisms would you expect ethanol fermentation to occur?

plants and fungi

If you've ever learned about beer making, you may know that some people add fruit juice to their yeast mixtures. Why?

to add glucose to the yeast

In glycolysis, ATP is synthesized by:

substrate-level phosphorylation.

In eukaryotic cells, the oxidation of pyruvate occurs in: the matrix of the mitochondria. vacuoles. the nucleus. the cytoplasm. the endoplasmic reticulum.

the matrix of the mitochondria.

At the end of glycolysis, the carbon molecules originally found in the starting glucose molecule are in the form of:

two pyruvate molecules