Chapter – 12
Respiration in Plants
Q1. The ultimate electron acceptor of respiration in an aerobic organism is
(a) Cytochrome
(b) Oxygen
(c) Hydrogen
(d) Glucose
Ans:
(b) The ultimate electron acceptor of respiration in an aerobic organism is oxygen.
Q2. Phosphorylation of glucose during glycolysis is catalyzed by
(a) Phosphoglucomutase
(b) Phosphoglucoisomerase
(c) Hexokinase
(d) Phosphorylase
Ans:
(c) Phosphorylation of glucose during glycolysis is catalyzed by hexokinase
Q3. Pyruvic acid, the key product of glycolysis can have many metabolic fates. Under aerobic condition it forms
(a) Lactic acid
(b) C02 + H20
(c) Acetyl CoA + C02
(d) Ethanol + CO
Ans:
(c) Pyruvic acid, the key product of glycolysis can have many metabolic fates. Under aerobic condition it forms Acetyl CoA + CO2.
Q4. Electron Transport System (ETS) is located in mitochondrial
(a) Outer membrane
(b) Inter membrane space
(c) Inner membrane
(d) Matrix
Ans:
(c) Electron Transport System (ETS) is located in mitochondrial inner membrane.
Q5. Which of the following exhibits the highest rate of respiration? .
(a) Growing shoot ap maex
(b) Germinating seed
(c) Root tip
(d) Leaf bud
Ans:
(b) Germinating seed exhibits the highest rate of respiration
Q6. Mitochondria are called powerhouses of the cell. Which of the following observations support this statement?
(a) Mitochondria synthesise ATP
(b) Mitochondria have a double membrane .
(c) The en 2ym es of the Krebs’ cycle and the cytochromes are found in mitochondria
(d) Mitochondria are found in almost all plant and animal cells
Ans:
(a) Mitochondria are called powerhouses of the cell because mitochondria synthesise ATP.
Q7. The end product of oxidative phosphorylation is
(a) NADH
(b) Oxygen
(c) ADP
(d) ATP + H20
Ans:
(d) The end product of oxidative phosphorylation is ATP+H2o
8. Energy is released during the oxidation of compounds in respiration. How is this energy stored and released as and when it is needed?
Ans:
Energy released during the oxidation of compounds in respiration is immediately stored in ATP in the form of chemical bonds.ADP + iP + energy —> ATP As and when needed, this bond energy is broken and utilised ATP —> ADP + iP + energy
Q9. Explain the term “Energy Currency”. Which substance acts as energy currency in plants and animals?
Ans:
Every function of the cell requires energy. Energy currency stores and releases the energy as and when needed in the cell. ATP is called energy currency in both plants and animals.
Q10. When does anaerobic respiration occur in man and yeast?
Ans:
In alcoholic fermentation (by yeast), incomplete oxidation of glucose occurs under anaerobic conditions by sets of reactions where pyruvic acid is converted to ethanol and C02.PA —> Ethanol + C02 In animal cells also, like muscles during exercise, when oxygen is inadequate for cellular respiration pyruvic acid is reduced to lactic acid.
Q11. The energy yield in terms of ATP is higher in aerobic respiration than during anaerobic respiration. Why is there anaerobic respiration even in organisms that live in aerobic condition like human beings and angiosperms?
Ans:
Anaerobic respiration even in organisms that live in aerobic condition like human beings and angiosperms due to the oxygen deficiency. In our skeletal muscles during strenuous exercise oxygen deficiency leads to anaerobic respiration. In germinating seeds anaerobic respiration leads to release of energy for emerging the seedling from the soil.