Respiration

Question 1

Respiration

Answer 1

• glucose cannot be used as energy source directly to cells, only ATP
• respiration is formation of ATP, break down of glucose

Question 2

Aerobic respiration

Answer 2

Requires oxygen

Produces CO2, water, ATP

Question 3

Glycolysis

Answer 3

• first stage in both aerobic and anerobic respiration
  No oxygen required
  Cytoplasm of all living cells

Question 4

Glycolysis

Sequence

Answer 4

1. Phosphorylation of glucose to glucose phosphate
   - glucose made reactive
   - 2 phosphate molecules from hydrolysis of 2ATP
   - lowers activation energy fro enzyme controlled reactions
2. Phosphorylase glucose is split
   - each glucose split into two triode phosphate (3C)
3. Oxidation of triode phosphate
   - hydrogen removed from each triode phosphate molecule
   - transferred to NAD to from reduced NAD
4. Production of ATP
   - enzyme controlled reactions convert each triode phosphate to pyruvate (3C)
   - 2 ATP regenerated from ADP

Final yield= 2 ATP, 2 reduced NAD, 2 pyruvate

Question 5

Link reaction

Answer 5

Matrix of mitochondria

1. Each pyruvate oxidised to acetate (2C)
   - pyruvate loses carbon dioxide + 2 hydrogens
   - hydrogens +NAD = 2 reduced NAD
2. Acetate combines with coenzyme A, produce compound, acetylcoenzyme A

Question 6

Krebs cycle

Answer 6

Matrix of mitochondria

1. Acetylcoenzyme A (2C) combines with 4C molecule = 6C molecule
2. Series of reactions, 6C molecule loses 2CO2 and hydrogen to give 4C molecule
   Single ATP produced from substrate - level - phosphorylation
3. 4C molecule combine with acetylcoenzyme A, begin cycle again

Final yield for each pyruvate link + jeans - reduced coenzymes FAD, NAD, 1 ATP, 3 CO2 (double this)

Question 7

Oxidative phosphorylation

Answer 7

Cristae of mitochondria

1. Hydrogen atoms produced in krebs + glycolysis combine with coenzymes NAD + FAD
2. Reduced NAD + FAD donate electrons of hydrogen atoms to first molecule in ETC
3. Electrons pass through ETC chain via oxidation - reduction reactions
   Energy realised cause active transport of protons from inter mitochondrial membrane to IM space
4. Protons accumulate, diffuse back into mitochondrial matrix through ATP synthase channels in inter mitochondrial membrane (ATP)
5. End of chain, electrons + protons + oxygen combine to form water
   Oxygen is final acceptor of ETC