Terminal Respiration

Question 1

Requirements for oxidation in terminal respiratory system of eukaryotic cells

Answer 1

NADH & FADH2 have to be in mitochondrial matrix

Question 2

Transfer of electrons from NADH to Electron Transport Chain

Answer 2

NADH + H+ -> NAD+
Dihydroxyacetone phosphate -> Glycerol 3-Phosphate

Glycerol 3-Phosphate gives electrons to FAD -> FADH2, FADH2 into Electron Transport Chain

Question 3

NADH-Q oxidoreductase (complex I) Function

Answer 3

• Oxidises NADH, passes high energy electrons to ubiquinone -> ubiquinol
• Intake of 2 protons, transport 4 hydrogens over inner mitochondrial membrane

Question 4

Succinate-Q reductase (complex II) Function

Answer 4

-Oxidises FADH2, passes high energy electrons to ubiquinone -> ubiquinol
(Succinate-Q reductase part of citrate acid cycle)

Question 5

Q-Cytochrome C Oxidoreductase (complex III) function

Answer 5

• Takes electrons from ubiquinol and passes them to Cytochrome C
• Ubiquinol oxidises -> 2 reduced Cytochrome C molecules
• Pumps protons into intermembrane space

Question 6

Cytochrome C Oxidase (complex IV) function

Answer 6

• Takes electrons from Cytochrome C and passes them to molecular O2
• Protons pumped into intermembrane space

Question 7

Where is NADH obtained from?

Answer 7

Glycolysis, Citric Acid Cycle, Beta-Oxidation

Question 8

Where is FADH2 obtained from?

Answer 8

Beta-Oxidation (and NADH via G-3-P Shuttle)

Question 9

What does pumping protons to intermembrane space do?

Answer 9

Intermembrane space becomes acidic, hence electrical gradient produced, energy is stored

Question 10

Process of ATP synthesis

Answer 10

• High concentration of protons in intermembrane space
• Proton goes down concentration gradient, back into matrix of mitochondria
• ATP synthase allows passage of protons, energy from gradient used for ADP +Pi -> ATP