Bio 150 LP Ch. 7

A simplified overall equation for respiration is as follows: C6H12O6 + 6O2 →6CO2+ 6H2O + energy In this reaction, we can say that _____ is reduced and _____ is oxidized.

oxygen; glucose

During which phase(s) of glycolysis do we observe pyruvate production, ATP synthesis, and reduction of NAD+?

payoff phase

Which process produces the highest number of reduced electron carriers and thus the greatest potential for generating ATP?

the citric acid cycle

In eukaryotes, fermentation takes place:

the cytoplasm

During the pyruvate oxidation stage of cellular respiration, which of the following occurs?

the formation of NADH, the oxidation of pyruvate, the formation of CO2, and the formation of acetyl-CoA

Which is the only reaction in the citric acid cycle that produces ATP by substrate-level phosphorylation?

the formation of succinate

We can tell from their structure that fatty acids are a good source of energy because of:

the large number of carbon-carbon and carbon-hydrogen bonds they contain

Which of the following is required for the preparatory phase of glycolysis and then produced during the payoff phase?

ATP

One of the enzymatic results of the pyruvate oxidation stage of cellular respiration is the reduction of _____to _____

NAD+; NADH

What product of the pyruvate oxidation stage of cellular respiration will have the two electrons that are lost from pyruvate?

NADH

Which of the following is an electron carrier in its reduced form?

NADH

In the cleavage phase of glycolysis:

a phosphorylated sugar molecule is broken apart and the products rearranged

In which organisms would you expect ethanol fermentation to occur?

fungi and plants

In cellular respiration, oxygen:

gains electrons and is reduced

Which of the following are inputs, but not outputs, of glycolysis?

glucose

The storage carbohydrate in animals is ___________ and in plants is _________

glycogen; starch

The breakdown of fatty acids takes place by a process called:

beta-oxidation

Cellular respiration is a series of _____ reactions.

catabolic

In eukaryotic cells, glycolysis occurs in:

cytoplasm

During what phase of glycolysis is NADH formed?

during phase 3, when glyceraldehyde 3-phosphate is phosphorylated

During glycolysis, pyruvate oxidation, and the citric acid cycle, the chemical energy in glucose is transferred to:

electron carriers and ATP

Tracing the metabolism of one glucose molecule, how many carbon atoms are fully oxidized to CO2 at the completion of glycolysis?

0

Oxidative phosphorylation yields _____ ATP for each molecule of FADH2 that is oxidized, whereas it yields _____ ATP for each molecule of NADH.

1.5;2.5

Which of the following is a net product of glycolysis?

2 pyruvate

Tracing the metabolism of one glucose molecule, how many carbon atoms are fully oxidized to CO2 at the completion of aerobic respiration?

6

Which best describes energy captured in ATP during aerobic cellular respiration?

A small amount of energy is captured in ATP by substrate-level phosphorylation; most is captured in ATP by oxidative phosphorylation

During a long bout of sustained exercise, in which order will your body's energy stores/sources be used?

ATP stored in muscle, glycogen stored in muscle, glycogen stored in the liver, fatty acids

The ethanol resulting from fermentation of glucose only accounts for four of the six starting carbon atoms. In which of the following are the other two carbon atoms found?

CO2

What is the fully oxidized product that results from the pyruvate oxidation stage of cellular respiration?

CO2

What happens when glucose is phosphorylated during phase 1 of glycolysis?

Glucose is destabilized so that it can be broken apart in phase 2

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 lactic acid, causing his blood to become more acidic

During the citric acid cycle, which is shown, what happens to the coenzyme A that is part of acetyl-CoA?

It is recycled for use in other reactions

Which best describes how ATP synthase converts the potential energy of the proton gradient to the chemical energy of ATP?

Kinetic energy from the flow of protons is converted to the kinetic energy of rotation of the Fosubunit; the rotation of the Fo subunit leads to rotation of the F1 subunit, which can then catalyze ATP synthesis

Which statement is true regarding pyruvate and glucose?

Pyruvate can be transported across both membranes of the mitochondrion to be further metabolized, but glucose cannot

A researcher is comparing the amount of protein contained in inner and outer mitochondrial membranes. What do you predict they will find?

The amount of proteins will be greater in the inner membrane

Glycolysis is:

anaerobic

Lactic acid fermentation occurs in

bacteria and animals

The first phase of glycolysis requires the input of two ATP molecules. It is therefore:

endergonic

Fermentation occurs only in anaerobic conditions

false

Fermentation produces nearly twice as much ATP as aerobic respiration, which explains why it is a preferred pathway for bacteria.

false

In a plant cell, the oxidative phosphorylation stage of cellular respiration is carried out in the cytoplasm.

false

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

false

Oxidation is the gain of electrons.

false

The glycolysis stage is responsible for producing most of the ATP during cellular respiration.

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

Which of the following is one explanation for why glycolysis is believed to have arisen very early in the evolution of life?

it does not require oxygen

Pyruvate oxidation is an important stage in cellular respiration because:

it links glycolysis with the citric acid cycle

When a substance in a reaction is oxidized, it:

loses electrons

The chemical bonds of carbohydrates and lipids have high potential energy because:

many of these bonds are C—C and C—H bonds, in which electrons are shared equally between atoms

In eukaryotes, pyruvate oxidation takes place in the

mitochondrial matrix

In eukaryotes, pyruvate oxidation takes place in the:

mitochondrial matrix

In what organelle is pyruvate oxidation carried out in a cell?

mitochondrion

The citric acid cycle is a cycle because the starting molecule, _____, is regenerated at the end.

oxaloacetate

The loss of electrons is referred to as:

oxidation

The mitochondrial electron transport chain is part of:

oxidative phosphorylation

Which stages of cellular respiration use O2 as an input?

oxidative phosphorylation

A molecule that is _____ loses electrons, and a molecule that is _____ gains electrons.

oxidized; reduced

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

oxidized; reduced

The final (terminal) electron acceptor of the electron transport chain is:

oxygen

Acetyl-CoA synthesis occurs during:

pyruvate oxidation

Which stage of cellular respiration occurs following production of pyruvate?

pyruvate oxidation

When you exhale, there is more CO2 than was present in the air that you inhaled. This CO2 comes from reactions in:

pyruvate oxidation and the citric acid cycle

Which stages of cellular respiration produce CO2 as a waste product?

pyruvate oxidation and the citric acid cycle

Which statement is true regarding pyruvate oxidation?

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

In pyruvate oxidation, the electron donor is _____ and the electron acceptor is _____.

pyruvate; NAD+

At the end of glycolysis, the carbon originally found in the starting glucose molecule is now present in:

two pyruvate molecules

The _____ forms of the electron carriers NAD+/NADH and FAD/FADH2 have high potential energy.

reduced

In glycolysis, ATP is synthesized by:

substrate-level phosphorylation

Coenzyme Q and cytochrome c:

transfer electrons between protein complexes of the electron transport chain

In addition to destabilizing glucose for subsequent breakdown, what else does phosphorylation of glucose do?

traps glucose inside the cell

Both NAD+ and molecular oxygen serve as electron acceptors in cellular respiration

true

Conditions that reduce the strength of the proton gradient across the inner mitochondrial membrane slow the production of ATP by ATP synthase.

true

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

true

When glucose is broken down in a cell, all of the energy it stores is not released simultaneously but is instead released in a stepwise process.

true

Although glycolysis produces four molecules of ATP by substrate-level phosphorylation, the net gain of ATP for the cell is two molecules. This is because:

two molecules are used in the initial stage

Which of the following summarizes the net final products of glycolysis?

two molecules of pyruvate, two molecules of ATP, and two molecules of NADH

Of the 6 carbons in a starting molecule of glucose, at the completion of pyruvate oxidation, _____ carbons are fully oxidized to _____, while _____ carbons remain in _____. Please choose the correct answer from the following choices, and then select the submit answer button.

two; CO2; four; acetyl groups

Which of the following is a product (as opposed to a substrate) of at least one of the processes of cellular respiration?

water