bioenergetics

Question 1

What is the primary function of mitochondria?

Answer 1

generate ATP through oxidative phosphorylation, providing energy for cellular processes.

Question 2

where does the TCA cycle take place

Answer 2

mitochondrial matrix

Question 3

where does oxidative phosphorylation take place

Answer 3

inner mitochondrial membrane

Question 4

What is the chemiosmotic theory?

Answer 4

explains how ATP is generated in mitochondria via a proton gradient across the inner mitochondrial membrane

Question 5

What generates the proton gradient in mitochondria?

Answer 5

electron transport chain

Question 6

How is oxygen involved in the chemiosmotic process?

Answer 6

the final electron acceptor

Question 7

What are the mobile electron carriers in the ETC?

Answer 7

Ubiquinone (Coenzyme Q) and cytochrome c

Question 8

What is the role of Complex I in the ETC?

Answer 8

oxidizes NADH, transfers electrons to ubiquinone, and pumps protons into the intermembrane space

Question 9

What is the role of Complex II?

Answer 9

oxidizes succinate in the citric acid cycle, transfers electrons to ubiquinone, but does not pump protons.

Question 10

What is the role of Complex III?

Answer 10

transfers electrons from ubiquinone to cytochrome c and pumps protons across the inner membrane.

Question 11

What is the role of Complex IV?

Answer 11

transfers electrons from cytochrome c to oxygen (the final electron acceptor), forming water, and pumps protons

Question 12

What is the primary function of the ETC?

Answer 12

To transfer electrons from NADH and FADH₂ to oxygen, while pumping protons to create a proton gradient that drives ATP synthesis

Question 13

How does Complex I generate a proton gradient?

Answer 13

pumps protons from matrix to intermembrane space

Question 14

What is the role of FADH₂ in the ETC?

Answer 14

donates electrons to complex II

Question 15

Where does ATP synthesis occur in the cell?

Answer 15

inner mitochondrial membrane

Question 16

What enzyme is responsible for ATP synthesis?

Answer 16

ATP synthase

Question 17

How does ATP synthase function?

Answer 17

uses the energy from the proton gradient generated by the ETC to rotate and synthesize ATP from ADP and Pi as protons flow through it

Question 18

What is the proton motive force?

Answer 18

the potential energy stored in the proton gradient

Question 19

How does the proton motive force power ATP synthase?

Answer 19

Protons flow back into the mitochondrial matrix through the F₀ subunit of ATP synthase, causing the F₁ subunit to rotate and catalyze the synthesis of ATP.

Question 20

ow many ATP molecules are produced per NADH and FADH₂ during oxidative phosphorylation?

Answer 20

NADH produces about 2.5 ATP molecules, and FADH₂ produces about 1.5 ATP molecules

Question 21

What is the efficiency of ATP production through the electron transport chain?

Answer 21

34-38 ATP molecules from one glucose molecule during cellular respiration.