Topic 12: Energy and Respiration Flashcards
(18 cards)
Definitions I:
(a) ATP
(b) Respiration
(c) RQ
(a) ATP: Molecule storing cellular energy. (1 mark)
(b) Respiration: Process releasing energy from substrates. (1 mark)
(c) RQ: CO₂ produced/O₂ used in respiration. (1 mark)
Outline the need for energy in a muscle cell. [2 Marks]
Energy for active transport, contraction (1 mark); Drives protein synthesis (1 mark). (2 marks)
Describe ATP’s features as the energy currency in a yeast cell. [2 Marks]
Small, unstable bonds release energy (1 mark); Universal, easily made/broken (1 mark). (2 marks)
State how ATP is synthesised in a plant leaf cell. [2 Marks]
Substrate-linked in glycolysis (1 mark); Chemiosmosis in mitochondria/chloroplasts (1 mark). (2 marks)
In a liver cell, explain the energy values of carbohydrates vs. lipids. [3 Marks]
Carbs: 17 kJ/g, quick energy (1 mark); Lipids: 39 kJ/g, stored energy (1 mark); Proteins less used (1 mark). (3 marks)
Calculate the RQ for glucose respiration in a germinating seed. [2 Marks]
C₆H₁₂O₆ + 6O₂ → 6CO₂; RQ = 6/6 = 1 (1 mark); Calculation shown (1 mark). (2 marks)
In a lab, describe how to measure RQ of blowfly larvae using a respirometer. [3 Marks]
Larvae in respirometer, measure O₂ used (1 mark); CO₂ absorbed by soda lime (1 mark); RQ = CO₂/O₂ (1 mark). (3 marks)
State where glycolysis and the Krebs cycle occur in a human cell. [2 Marks]
Glycolysis: Cytoplasm (1 mark); Krebs: Mitochondrial matrix (1 mark). (2 marks)
In a muscle cell, outline glycolysis during a sprint. [3 Marks]
Glucose phosphorylated, splits to triose (1 mark); Oxidised to pyruvate (1 mark); Makes ATP, reduced NAD (1 mark). (3 marks)
Describe the link reaction in a mitochondrion of a skin cell. [2 Marks]
Pyruvate to acetyl CoA, CO₂ released (1 mark); Coenzyme A transfers acetyl (1 mark). (2 marks)
Outline the Krebs cycle in a heart cell’s mitochondrion. [3 Marks]
Oxaloacetate + acetyl forms citrate (1 mark); Series of steps regenerates oxaloacetate (1 mark); Releases CO₂, energy (1 mark). (3 marks)
Explain NAD and FAD’s roles in a kidney cell’s respiration. [2 Marks]
NAD/FAD accept H from substrates (1 mark); Transfer to electron transport chain (1 mark). (2 marks)
In a neuron, describe oxidative phosphorylation in mitochondria. [4 Marks]
H splits, electrons energise chain (1 mark); Protons pumped, return via ATP synthase (1 mark); Energy forms ATP (1 mark); O₂ makes H₂O (1 mark). (4 marks)
Relate mitochondrial structure to function using a liver cell diagram. [3 Marks]
Cristae increase area for chain (1 mark); Matrix holds Krebs enzymes (1 mark); Double membrane isolates (1 mark). (3 marks)
Outline anaerobic respiration in yeast during fermentation. [2 Marks]
Glucose to ethanol, CO₂ (1 mark); No O₂, less ATP (1 mark). (2 marks)
Using DCPIP, investigate temperature effects on yeast respiration rate. [3 Marks]
Mix yeast, DCPIP, vary temp (1 mark); Blue fades faster at optimum (1 mark); Measure rate (1 mark). (3 marks)
In a flooded rice plant, explain adaptations for anaerobic respiration. [4 Marks]
Aerenchyma channels O₂ to roots (1 mark); Ethanol fermentation sustains energy (1 mark); Fast stem growth escapes water (1 mark); Adapts to flooding (1 mark). (4 marks)
Analyse how substrate concentration affects respiration rate in a respirometer. [4 Marks]
Vary glucose in respirometer (1 mark); O₂ uptake rises with substrate (1 mark); Plateaus at enzyme limit (1 mark); Rate reflects respiration (1 mark). (4 marks)
