Unit 2 - Exam Review

Question 1

2.1 Aerobic Respiration - 4 Steps + locations

Answer 1

Glycolysis (cytoplasm), pyruvate oxidation (mitochondria), krebs cycle (matrix of mitochondria), ETC and chemiosmosis (inner mitochondrial membrane)

Question 2

2.1 Anaerobic Respiration

Answer 2

Glycolysis only, NADH is recycled, lactic acid is produced and must be catabolised by repaying oxygen debt.

Question 3

2.2 Glycolysis - 4 steps + products

Answer 3

6 carbon glucose is split into two 3 carbon pyruvate.
1. Glucose activation
2. Sugar splitting
3. Oxidation
4. Formation of ATP
Products: 2ATP and 2NADH net

Question 4

2.2 Pyruvate Oxidation - 3 steps

Answer 4

1. Decarboxylisation
2. Pyruvate is oxidised by NAD+
3. 2 pyruvate -> acetlyCoA

Question 5

2.2 Krebs Cycle - 8 Steps + products

Answer 5

Oxaloacetate
Citrate
Isocitrate
aKetogluterate
SuccinylCoA
Succinate
Fumerate
Malate
Products: 2FADH2, 6NADH, 4CO2, 2ATP

Question 6

2.2 ETC and Chemiosmosis - Briefly explain

Answer 6

NADH and FADH lose their electrons to the first complex, electrons travel through complexes in a series of redox rxns, H ions are pumped out and back into the cytochrome complex to make ATP

Question 7

2.3 Related metabolic pathways

Answer 7

Protein -> amino acids -> deamination
Nucleic acid -> nucleotides
Carbs -> polysaccharides -> simple sugars -> glycolysis
Lipids -> triglycerides -> glycerol -> glucose -> glycolysis… fatty acids -> acetylCoA -> krebs cycle

Question 8

3.1 Chlorophyll structure + functions

Answer 8

Porphyn ring (absorbs light) and a hydrocarbon tail (phytol chain anchor)

Question 9

3.2 Name 3 accessory pigments + use

Answer 9

B-Carotene - Forms vitamin A
Xanthopylls - Yellow autumn leaves
Anthocyanins - Red autumn leaves

Question 10

3.3 Name 3 majors steps of PS + location

Answer 10

Light rxn (thylakoid membrane)
Carbon fixing (stoma)
Calvin Cycle (chloroplasts)

Question 11

3.3 Explain step 1 of PS light rxn

Answer 11

Light excites electrons in chlorophyll, water splits to make ATP and NADP. Photoexcitation -> E- transport -> Chemiosmosis

Question 12

3.3 Explain step 2/3 of PS carbon fixing/calvin cycle

Answer 12

CO2 enters the stoma and is fixed into glucose (G3P) by RuBP. Carbon fixation -> Reduction rxn -> Regeneration of RuBP

Question 13

3.4 Gas exchange in plants description + location - CR, PS, PR

Answer 13

CR: Mitochondria, O2 -> CO2
PS: Chloroplasts, CO2 -> O2
PR: Chloroplast, O2 -> CO2

Question 14

3.4 Three types of plants - location of plants, PR rate, location of calvin cycle, first enzyme

Answer 14

C3 - all plants, high, stroma, rubisco
C4 - tropical, low, bundle sheath, PEP carboxylase
CAM - desert, low, calvin during day, PEP carboxylase

Question 15

3.5 Photosynthesis and the environment, equation

Answer 15

Net CO2/O2 = PS-PR-CR

Question 16

3.6 PS vs PR

Answer 16

PR occurs when there is excess O2 that binds to RuBP, PR produces glycolate instead of glucose

Question 17

3.6 Chloroplast vs Mitochondria

Answer 17

Chloroplast - PS, H20 + CO2 -> O2 + C6H12O6, has ETC, H+ pumped out
Mitochondria - CR, C6H12O6 + O2 -> H2O + CO2, has ETC, H+ pumped in