Respiration

Question 1

Glycolysis

Answer 1

1. Phosphorolating glucose to glucose phosphate using ATP
2. Production of triose phosphate
3. Oxidation of triose phosphate to produce pyruvate, with a net gain of 2ATP and 2NADH

-Occurs in the cytoplasm
-Anaerobic prosses

Question 2

Link reaction

Answer 2

1. Pyruvate is oxidized to acetate. Decarboxylated, and NAD is reduced into NADH
2. Acetate combines with coenzyme A to produce acetyl CoA

-2 acetyl CoA
-2Co2
-2NADH

Question 3

Krebs cycle

Answer 3

1. Acetyl CoA reacts with a 4C molecule, releasing coenzyme A, and producing a 6-carbon compound
2. In a series of redox reactions, the Krebs cycle generates reduced coenzymes and ATP by substrate-level phosphorylation, and Co2 is lost

Per cycle:
-3 NADH
-1FAD
-1 ATP
-2 Co2

Question 4

Oxidative phosphorylation

Answer 4

1. Reduced NAD and reduced FAD deliver H atoms
2. They become oxidised and return to the matrix to collect more
3. The hydrogen is split into electrons and H+ ions
4. The electrons are passed down the carrier proteins in the membrane, and the energy this releases moves the H+ across the membrane (into the intermembrane space), against the concentration gradient
5. O2 is the final electron acceptor and collects the electrons along with the H+ ions to create water
6. The H+ in the intermembrane space moves back to matrix, down the concentration gradient, through ATP synthase to create ATP

-28 ATP made
-Uses NADH and FADH made in earlier stages
-Occurs at cristae

Question 5

Anaerobic respiration

Answer 5

-Reduced NAD reacts with pyruvate to produce NAD and lactate
-If NAD weren’t regenerated, glycolysis would stop because there would be no NAD available to accept electrons and protons in glycolysis
-Lacate removed to liver to be converted to glycogen