B18

Question 1

Respiration

Answer 1

C6H12O6 + 6O2 –> 6CO2 + 6H2O + ENERGY.
Energy needed to Energy releas- Excess
break bonds. ed in bond for- used to
mation. synthesise
ATP.
Respiratory Quotient (RQ) = CO2 (produced) divided by O2 (consumed).

Question 2

ATP synthesis

Answer 2

ADP + Pi –> ATP using ATPsynthase.

Question 3

ATP hydrolysis

Answer 3

ATP –> ADP + Pi using ATPase. +30.6kJ.mol-1.

Question 4

Mitochondria

Answer 4

Outer membrane
Intermembrane space
Inner membrane
Cristae
Matrix.

Question 5

Coenzymes

Answer 5

NAD/FAD/CoA.
Aid enzyme function, transfer chemical group between mols. (e.g. H+).

Question 6

Phosphorylation

Answer 6

+ phosphate mol.

Question 7

Stages of Aerobic Respiration

Answer 7

1. Glycolysis, cytoplasm (no O2).
2. Link Reaction, matrix (O2).
3. Krebs Cycle, matrix (O2).
4. Oxidative Phosphorylation, cristae (O2).

Question 8

Glycolysis

Answer 8

Phosphorylation, lysis, oxidation, substrate level phosphorylation.
1 glucose forms NET = +2 ATP, +2 NADH, +2 Pyruvate.
(ATP/NADH active trpt into matrix).

Question 9

Link Reaction

Answer 9

Oxidation pyruvate –> acetate. Acetate accepted by Coenzyme A, form Acetyl CoA.
1 glucose forms NET = +2 ATP, +4 NADH, +2 CO2, +2 Acetyl CoA.

Question 10

Krebs Cycle

Answer 10

Acetyl CoA release acetyl.
Acetyl + oxaloacetate –> citrate.
Input 3NAD/1FAD/ADP/Pi per turn.
ATP produced by substrate level phosphorylation of ADP + Pi.
Each turn forms oxaloacetate ready to rejoin with acetyl.
1 glucose forms NET = +4 ATP, +10 NADH, +2 FADH, +6 CO2.

Question 11

Oxidative Phosphorylation

Answer 11

Input 10NADH/2FADH along e- transport chain.
Complex I separate NAD from H (reoxidised), release e- which is passed along chain.
Complexes I/III/IV H+ pumped into intermembrane space, est. PROTON GRADIENT.
Membrane impermeable to H+ so diffuses down proton channel, spinning globular head which drives ATP synthase (ADP + Pi –> ATP) (oxidative phosphorylation).
1 glucose forms NET = 38 ATP.

Question 12

Anaerobic Respiration (Animals)

Answer 12

LACTIC FERMENTATION:
regenerate NAD to accept more H in glycolysis.
pyruvate —–> lactate + NAD using lactic dehydrogenase. (pyruvate reduced by NADH forming lactic acid, H donated to pyruvate).
1 glucose = +2 ATP.

Question 13

Anaerobic Respiration (Plants)

Answer 13

ALCOHOLIC FERMENTATION:
pyruvate –> ethanal (+CO2) using pyruvate decarboxylase.
ethanal –> ethanol (+NAD) using alcohol dehydrogenase.
1 glucose = +2 ATP.

Question 14

Obligate anaerobes

Answer 14

Cannot survive in presence of oxygen. Usually prokaryotes and some fungi.

Question 15

Facultative anaerobes

Answer 15

Synthesis ATP by aerobic resp if oxygen present, but can switch to anaerobic in its absence.

Question 16

Obligate aerobes

Answer 16

Can only synthesis ATP in presence of oxygen, e.g. mammals.