Cellular respiration and photosynthesis

Question 1

Main points of aerobic cell respiration

Answer 1

1. Glycolysis - 2 NADH, 2 Pyruvate
2. Link reaction (oxidative decarboxylation) - Pyruvate —> 2 Acetyl CoA
3. The Krebs cycle - 2 CO2
4. Oxidative phosphorylation - electron transport chain, chemiosmosis - H2O

Question 2

Main points of anaerobic cell respiration

Answer 2

1. Glycolysis
2. Fermentation - lactic acid + 2NAD+ / ethanol + CO2 + 2NAD+

Question 3

Where does glycolysis take place?

Answer 3

Cytoplasm

Question 4

Where does the link reaction take place?

Answer 4

Pyruvate passes to the mitochondrial matrix

Question 5

ATP characteristics:

Answer 5

Adenosine Triphosphate
- can be regenerated (by cell respiration, photosynthesis)
- soluble
- bond between 2 and 3 phosphate group releases energy when broken

Question 6

ADP

Answer 6

Adenosine Diphosphate

Question 7

Difference in molecules that aer vs ana can decompose

Answer 7

carbohydrates, lipids, amino acids vs just carbohydrates

Question 8

Oxygen debt

Answer 8

the amount of oxygen that must be absorbed following anaerobic respiration

Question 9

Lactic acid production is ceased (tired)

Answer 9

the pH in the blood would be too high

Question 10

What affects the rate of cell respiration?

Answer 10

• Concentration of Oxygen / Hydrogen
• Temperature
• Glucose levels (respiratory substrate)
• CO2 concentration

Question 11

Where are photosystem located?

Answer 11

Chloroplast (Eukaryotic) / cell membrane (Prokaryotic) —> Thylakoid membranes

Question 12

PS II —> PS I

Answer 12

electrons from photolysis, ATP —> e from PS II, NADPH

Question 13

Photolysis

Answer 13

splitting of water (replaces electrons) using energy from light, O2 byproduct

Question 14

Chemiosmosis in photosynthesis

Answer 14

pass down the electron transport chain, powers proton pumps, pump protons into the Thylakoid space, p passively diffuse through ATP synthase

Question 15

RuBisCO

Answer 15

Enzyme responsible for carbon fixation, attachment of CO2 to RuBP (Ribulose Biphosphosphate)

Question 15

G3P + NADPH + ATP —> TP + NADP + ADP

Answer 15

Glycerate 3 Phosphate —> Triose Phosphate

Question 16

2 TP —>

Answer 16

6 C glucose / with additional minerals amino acids or lipids

Question 17

Light dependent reaction

Answer 17

Photosystem II (Photolysis 4H+ + 4e + O2) —> Photosystem I (2e —reductase-> 2NADPH), ATP synthase

Question 18

Light independent reaction

Answer 18

Calvin cycle, in the Stroma

Question 19

Proton gradient

Answer 19

Difference in p concentration across a membrane

Question 20

Carbon fixation

Answer 20

Convergence of inorganic C compounds (CO2) to organic molecules, done by living organism

Question 21

Membrane proteins - functions

Answer 21

• electron carriers
• active transport - proton gradient
• cell recognition
• enable facilitated diffusion

Question 22

Oxidative decarboxylation of pyruvate

Answer 22

NAD+ is reduced CO2 produced

Question 23

Link reaction

Answer 23

2 Pyruvate —> oxidative decarboxylation —> Acetate (+CoA) —> 2 Acetyl Coenzyme A + 2CO2

Question 24

Glycolysis

Answer 24

Phosphorylation - 2 PO3 added to destabilise glucose
Lysis - Hexose Biphosphate is split to form 2 Triose phosphates
Oxidation - 2 3-C are dephosphorylated to form 2 pyruvate

Question 25

Calvin cycle

Answer 25

Carbon fixation —> reduction —> regeneration of RuBP