BIO EXAM 2 Ch 7

The citric acid cycle takes place in the:

mitochondrial matrix.

The reaction depicted pyruvate oxidation doing: Select all that apply

occurs in the mitochondrial matrix, shows the formation of the molecule that enters the citric acid cycle, occurs twice for each glucose that starts glycolysis.

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

oxaloacetate

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

oxidized; reduced

What is the final electron acceptor in the electron transport chain?

oxygen plus hydrogen forming water

During the important redox reactions of electron transport chain, the transfer of electrons is typically accompanied by transfer of:

protons.

During which stages of cellular respiration is carbon dioxide released? Select all that apply.

pyruvate oxidation and the citric acid cycle

The main purpose of the citric acid cycle is to:

reduce the co-enzymes NAD+ and FAD.

At the end of glycolysis, what net products do you have total?

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

At the end of glycolysis, the 6-carbon atoms originally found in the glucose molecule are now in:

two pyruvate molecule.

Which example represents the reduced forms of the two major electron carriers?

NADH and FADH2

Energy released by transferring electrons along the electron transport chain is stored as potential energy in the form of:

a proton gradient in the intermembrane space.

What is most likely to have been the first metabolic pathway or structure to evolve?

fermentation

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

glucose

Which of the following are net products of the citric acid cycle for each molecule of acetyl-CoA that enters? Select all that apply.

3 NADH, 1 ATP, 1 FADH2

In Phase 2: Cleavage Phase of glycolysis:

A 6-carbon molecule is split into two 3-carbon molecules.

Which statement best describes how ATP is made 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 Phase 3: Payoff Phase of glycolysis, what happens?

ATP is made, NAD+ is reduced to NADH and 2 pyruvate molecules are formed

During the citric acid cycle:

ATP is synthesized by substrate-level phosphorylation.

The proton concentration gradient created by the E.T.C. requires the protons to flow from high to low concentration through the ______ which forms a ton of ATP as it spins within the membrane.

ATP synthase.

What happens to pyruvate during fermentation?

It is reduced to ethanol or lactic acid.

Which of the following is the most important product of the fermentation pathway in animal cells?

NAD+

Which of the following statements is true regarding pyruvate and glucose?

Pyruvate can be transported into the matrix of the mitochondria, but glucose cannot.

In what ways would you characterize the process of fermentation? Select all that apply.

a useful process in the production of alcohol, a useful process in the production of cheese and yogurt, a useful process for organisms that were present when there was very little atmospheric oxygen, a limited way of deriving energy without oxygen, as the amount of ATP generated in fermentation is low

Each round of the citric acid cycle begins when the four-carbon molecule oxaloacetate combines with _____ to form the six-carbon molecule citrate. As the cycle progresses, two carbons are eliminated to regenerate the oxaloacetate. The two eliminated carbons are released as _____

acetyl-CoA; CO2

Glycolysis is:

anaerobic

An organism that carries out cellular respiration in its mitochondria:

could be a cell from a terrestrial (land) plant.

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

electron carriers and ATP.

The proteins that make up the electron transport chain are:

embedded in the inner mitochondrial membrane.

In eukaryotes, fermentation takes place:

in the cytoplasm.

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

intermembrane space; mitochondrial matrix

Pyruvate oxidation is an important stage in cellular respiration because:

it links glycolysis with the citric acid cycle.

In human cells, such as those in muscle tissue, the product of fermentation is:

lactic acid.

In glycolysis, ATP is synthesized by:

substrate-level phosphorylation.

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.