4.4.2 Oxidative Phosphorylation

Question 1

Review of Respiration:

Answer 1

· Glucose is broken down into pyruvate through the process of glycolysis.
· Pyruvate moves into the mitochondria and is converted to acetyl CoA.
· Still in the mitochondria, acetyl CoA enters the Krebs cycle, where it is further broken down and many coenzymes are reduced.
· Electrons and protons from reduced coenzymes enter the electron transport chain where they are used to create a proton gradient across the inner mitochondrial membrane. This gradient will be used to drive the synthesis of ATP.

Question 2

ATP synthase

Answer 2

• protein complex that can make ATP from the movement of H+ down the concentration gradient set up by the electron transport chain

Question 3

chemiosmosis

Answer 3

• describes the movement of ions down a gradient. This movement of ions drives the production of ATP

Question 4

oxidative phosphorylation

Answer 4

• the process of ATP production that is driven by the oxidation (and reduction) reactions that take place in the electron transport chain.

Question 5

note

Answer 5

• Mitochondria have a double membrane. The inner membrane is highly folded and encloses the mitochondrial matrix. The folds of the inner membrane are called cristae. The space between the inner and outer membrane is called the intermembrane space.
• Energy gained from the transfer of electrons is used to pump H+ into the intermembrane space of the mitochondria. This concentration gradient causes one side of the membrane to have a charge while the other side has little to no charge. H+ will diffuse across the membrane through ATP synthase. The downhill flow of H+ through ATP synthase drives the production of ATP.

Question 6

Protons are equivalent to

Answer 6

• hydrogen ions

Question 7

True or false?

Oxidative phosphorylation does not occur during glycolysis or the Krebs cycle.

Answer 7

• true

Question 8

Oxidative phosphorylation

Answer 8

• uses the diffusion of protons down a gradient to fuel ATP synthesis.

Question 9

The intermembrane space of the mitochondrion is

Answer 9

• more acidic than the matrix

Question 10

The energy for proton-gradient formation comes from:

Answer 10

• Exergonic redox reactions.

Question 11

True or false?

Oxygen functions as the final electron acceptor in the Krebs cycle.

Answer 11

• false

Question 12

Energy is required to create the phosphate bond between inorganic phosphate and ADP during oxidative phosphorylation, this energy comes from:

Answer 12

• the charge gradient across the inner membrane of the mitochondrion

Question 13

Which statement regarding the chemiosmotic mechanism is false?

Answer 13

• ATP is required for the protons to diffuse across the membrane