Chapter 14 quiz

In mitochondria, with the complete breakdown of glucose, about how many molecules of ATP can be produced for each molecule of glucose oxidized?

30

Which of the following drives the production of ATP from ADP and Pi by ATP synthase?

A proton gradient

What is the main chemical energy currency in cells?

ATP

What occurs when ATP synthase pumps H+ across a membrane against the electrochemical proton gradient?

ATP synthase catalyzes the formation of ATP from ADP and Pi

Which of the following organisms do not have mitochondria in their cells?

Bacteria

Which of the following statements is true about the electron transport chain?

Electrons start out at very high energy and lose energy at each transfer step.

The organelles that produce ATP in eukaryotic cells:

Evolved from bacteria engulfed by ancestral cells billions of years ago.

Why does a single molecule of NADH result in the production of more ATP molecules than a single molecule of FADH2 via oxidative phosphorylation?

FADH2 feeds its electrons into the electron transport chain further along the chain.

It is energetically favorable for protons to flow in which direction?

From the intermembrane space to the mitochondrial matrix

Which of the following is not a direct source of fuel for mitochondria?

Glucose

In the electron transport chain, what provides the main reservoir for protons that are pumped across the membrane?

H2O

What is the ratio of ATP and ADP concentrations in the cytosol of a cell?

High ATP/ADP ratio

In a eukaryotic cell, where are most of the proteins for the electron transport chain located?

In the mitochondrial inner membrane

In mitochondria, what is the final electron acceptor in the electron transport chain?

Molecular oxygen (O2)

The electron transport chain accepts high-energy electrons from:

NADH & FADH2

Which of the following processes involves a membrane?

Oxidative Phosphorylation

In the electron transport chain, as electrons move along a series of carriers, they release energy that is used to:

Pump protons across a membrane.

Which of the following is NOT true of mitochondria?

They are replaced by chloroplasts in plants

T/F: Mitochondria can change their location, shape, and number in the cell to suit the needs of a cell.

True

T/F: NADH has a weak affinity for electrons and a negative redox potential.

True

T/F: The outer membrane of a mitochondrion is permeable to all small molecules, including small proteins.

True

T/F: The proton gradient can drive the active transport of metabolites into and out of the mitochondrion.

True

Ubiquinone has a redox potential of +30 mV, while cytochrome c has a redox potential of +230 mV. In the electron transport chain, electrons flow from:

Ubiquinone to cytochrome c

Which of the following statements is NOT true of electron transfer in the electron transport chain?

When an electron carrier accepts an electron, it becomes oxidized.

As electrons move through the electron transport chain, they are passed from:

a carrier molecule of lower electron affinity to a carrier molecule of higher electron affinity.

ATP synthase:

can either produce or break down ATP depending on the magnitude of the electrochemical proton gradient.

NADH has a strong tendency to:

donate electrons

The electron transport chain pumps protons:

from the matrix to the intermembrane space.

When the difference in redox potential between two pairs of molecules is highly positive, then the transfer of the electrons is:

highly favorable.

Cellular respiration:

is more efficient at generating energy than a gasoline-powered engine.

When protons move down their electrochemical gradient into the mitochondrial matrix, they:

produce ATP.

The movement of electrons through the electron transport chain:

pumps protons across the inner mitochondrial membrane.

When O2 accepts electrons in the electron transport chain, O2 becomes _______.

reduced