chapter 7 review questions

What is the net number of ATP generated directly during glycolysis per molecule of glucose?

2

What are the products of one turn of the citric acid cycle?

2 CO2, 3 NADH, 1 FADH2, 1 ATP

When substrate-level phosphorylation occurs, it means that __________.

ADP is converted into ATP by the addition of a phosphate group

The citric acid cycle occurs in the mitochondria. There are nine biochemical reactions involved in the citric acid cycle, and they are highly ordered. Select the correct order from the following choices. (Note: These are abbreviated and do not show NAD, ADP, ATP, or FAD.)

Acetyl-CoA joins the citric acid cycle and unites with oxaloacetate →forming citrate →which forms alpha-ketoglutarate → which forms succinyl-CoA → which forms succinate → which forms fumarate → which forms malate → which forms oxaloacetate

When yeast cells metabolize glucose in the absence of oxygen, which of the following are true?

All ATP is made by substrate-level phosphorylation, glycolysis occurs, ethanol is produced, NAD+ is regenerated from NADH, they produce less ATP than they produce in aerobic respirations

How does the ATP yield from aerobic respiration of one glucose molecule differ in prokaryotes and eukaryotes?

Eukaryotes yield 30 instead of 32 ATP, because of the cost of transporting two NADH into the mitochondria.Correct

Succinate is oxidized to fumarate using ________ as the electron acceptor.

FAD

What is the oxidized form of the most common electron carrier that is needed for both glycolysis and the citric acid cycle?

NAD+

During oxidative phosphorylation, _______ and FADH₂ are oxidized to power ATP production.

NADH

Aerobic respiration is ultimately the reaction of glucose with oxygen to generate carbon dioxide, water, and energy. However, in a cell this process involves the transfer of electrons from glucose to carriers such as NAD+ over a lengthy series of steps. Why don't cells employ the direct reaction of glucose with oxygen to generate energy?

The direct transfer of electrons from glucose to oxygen occurs via a combustion reaction that is incompatible with life.

A 2-carbon group from ___________ enters the cycle.

acetyl-CoA

In animals that take in oxygen from their environment, glucose is broken down into carbon dioxide and water in a process called __________.

aerobic respiration

Organisms that can manufacture their own chemical energy are called ____________.

autotrophs

NADH and FADH₂ donate _____________ at different points in the ETC

electrons

During what step of glycolysis are two ATP molecules required?

glucose priming

In cellular respiration, what pathway directly generates ATP for the cell?

glycolysis

What aspect of cellular respiration occurs in the cytoplasm in eukaryotic cells?

glycolysis

What stage of cellular respiration can occur in human cells with or without oxygen present?

glycolysis

When cells possess plentiful amounts of ATP, what happens to cellular respiration processes within the cell?

glycolysis is slowed

Organisms that depend on the energy stored in chemical bonds by other organisms for their food energy are called ____________.

heterotrophs

ATP synthase uses an electrochemical gradient of _______________ to produce ATP.

hydrogen ions

In the first half of the citric acid cycle, _____________ is oxidized, yielding a pair of electrons that reduce a molecule of NAD+ to NADH.

isocitrate

In the reaction: C3H7O6P + NAD+ →→ C3H8O10P2 + NADH, what happened to the NAD+?

it was reduced

The ETC is located in the inner membrane of the

mitochondrion

Malate is oxidized, yielding a 4-carbon molecule of _______________ and two electrons.

oxaloacetate

To form NADH from NAD+, two electrons and a proton are removed from an organic molecule. What term best describes the reaction in which electrons are removed from an organic molecule?

oxidation

The final electron acceptor of the ETC is

oxygen

What is an end-product of glycolysis?

pyruvate

You would like to study the activity of glycolysis in a cell undergoing cellular respiration in the presence of ample oxygen. Assuming you could experimentally measure the level of any product of cellular respiration, which product would you want to measure to determine the output of glycolysis?

pyruvate

A second oxidation produces _____________ and two electrons.

succinyl-CoA

All of the reactions of cellular respiration that occur after glycolysis take place in what part of the eukaryotic cell?

the mitochondria

What must happen to amino acids before they can be used in catabolic reactions?

they must be deaminated

Why are the components of the electron transport chain embedded in the inner mitochondrial membrane rather than floating freely in the cytoplasm of mitochondrial matrix?

to generate and maintain protein gradient essential for ATP production