Energy production: mitochondria and TCA cycle

Question 1

Name some roles of mitochondria

Answer 1

• Used to generate energy in the form of ATP
• Regulate cytosolic Ca2+ concentrations
• Buffer redox of cells (NAD+/NADH)
• Apoptosis
• Produce heat

Question 2

Describe Krebs/Citric acid cycle

Answer 2

• Occurs in matrix of mitochondria
• Produces CO2 as waste product, uses pyruvate

Question 3

Function of NAD+ and FAD

Answer 3

• FAD accepts electrons to become FADH2 (this is its reduced form)
• NAD+ is an oxidising agent, accepts electrons to become NADH (reduced form)
• These are then taken to ETC

Question 4

Describe the process of Oxidative phosphorylation and where it ocurs

Answer 4

• Occurs in inner membrane
• Relies on Fe and Cu to transfer electron carriers
• FADH2 and NADH release electrons
• Energy releases used to produce ADP + Pi - ATP
• Energy used to AT protons from matrix to inner membrane
• They diffuse down gradient via ATP synthase
• Releasing energy for ADP + Pi - ATP
• Oxygen is the final electron accepter which combines to form water

Question 5

Name the TWO metal ions that are essential for oxidative phosphorylation

Answer 5

Fe and Cu