bio ch 7

oxidative phosphorylation

The mitochondrial electron transport chain is part of:

two molecules are used in the initial stage.

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:

ATP is synthesized by substrate-level phosphorylation

During the citric acid cycle

NADH and FADH2.

The immediate source of electrons for the electron transport chain is:

electron carriers and ATP.

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

anaerobic.

Glycolysis is:

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mitochondrion

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

mitochondrial matrix

The citric acid cycle takes place in the:

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It is an electrochemical gradient.

Which statement describes the proton gradient generated by the electron transport chain?

These organisms likely carried out fermentation and may have had rudimentary proton pumps

Which statement is true regarding Earth's earliest organisms?

beta-oxidation.

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

substrate-level phosphorylation.

In glycolysis, ATP is synthesized by:

it links glycolysis with the citric acid cycle.

Pyruvate oxidation is an important stage in cellular respiration because:

complex I, coenzyme Q, complex III, cytochrome c, complex IV, oxygen

An electron from NADH entering the electron transport chain would travel among components of the chain in what sequence?

reduction of acetaldehyde, derived from pyruvate

Which of the following describes the key reactions in fermenting beer, wine, or other alcoholic beverages?

glycogen in animals.

Excess glucose is stored in large branched molecules of:

during phase 3, when glyceraldehyde 3-phosphate is phosphorylated

During what phase of glycolysis is NADH formed?

CO2, FADH2, NADH, and ATP

Some bacteria run the citric acid cycle in reverse. Without any other modifications to the cycle, what inputs would be required to do this?

from rotational energy provided by the flow of protons through the channel in the Fo subunit

Where does the F1subunit of ATP synthase get its energy to catalyze the synthesis of ATP?

Ethanol fermentation produces CO2 as a byproduct, but lactic acid fermentation does not.

Lactic acid and ethanol fermentation differ in that:

Different sugars can be modified to form different intermediates of glycolysis.

We consume a variety of carbohydrates that are digested into a variety of different monosaccharides. How do these different sugars enter glycolysis?

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

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

NAD+; NADH

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

they are released as CO2 byproducts.

In the citric acid cycle, after the acetyl-group (2C) from acetyl-CoA is transferred to oxaloacetate (4C) to produce citrate (6C), subsequent reactions eventually result in 4C intermediates that are rearranged to regenerate oxaloacetate. What happens to the other two carbons?

oxidized; reduced

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

2; 3; 2; 2

Starting from glucose, lactic acid fermentation results in _____molecules of lactic acid, each with _____ carbons, whereas ethanol fermentation results in _____ molecules of ethanol, each with _____ carbons.

glycogen; starch

The storage carbohydrate in animals is ___________and in plants is __________.

oxygen; glucose

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.

payoff phase

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

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

Which statement is true regarding pyruvate and glucose?

oxidation; NADH

During the citric acid cycle, the production of CO2is the result of the _____of intermediate compounds of the citric acid cycle coupled to the production of _____.

intermembrane space; mitochondrial matrix

Due to the pumping action of the electron transport chain, protons have a high concentration in the _____and a low concentration in the _____.

because these metabolic processes are found in nearly all organisms

Why do we believe that glycolysis and fermentation probably evolved very early in the history of life in an ancestor to essentially all life on Earth?

traps glucose inside the cell

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

a phosphorylated sugar molecule is broken apart and the products rearranged.

In the cleavage phase of glycolysis:

It does not require oxygen

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

two pyruvate molecules.

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

NADH

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

pyruvate; NAD+

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

CO2

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

glucose

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

water

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

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

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