NEET Biology Respiration in Plants Important Questions Set 02

These Class 11 NEET Biology important questions on Respiration in Plants give 19 questions with step-by-step answers, arranged as very short, short and long answer types, taken from a model test paper. They help NEET aspirants revise the definitions, structures, differences and key terms of the chapter.

Very Short Answer Type Questions

Question 1. Define respiration.
Answer: It is a process of biological oxidation of organic molecules (i.e., breaking up of the C – C bonds) by using enzymes and which results in the release of energy in the form of ATP.

Question 2. Write down the step of Krebs cycle which releases GTP in cell respiration.
H₂O CoA Succinate thiokinase

Answer:

Succinyl CoA Succinic acid

GDP GTP

Question 3. Metabolic water as a by-product is released in both types of respiration i.e., aerobic and anaerobic respiration or in only one, if yes state in which it is released?
Answer: It is released only in aerobic respiration.

Question 4. Name the substrate which enters the Krebs cycle and is required continuously for uninterrupted cycle.
Answer: Acetyl CoA.

Question 5. Complete the equation: + + + —A → + + Pyruvic acid CoA NAD C D E B + + + —Mg²+ → + + + +
Answer: Pyruvic acid CoA NAD Acetyl CoA CO₂ NADH H Pyruvate dehydrogenase

Short Answer Type Questions

Question 6. What is respiratory quotient and name the respiratory substrate which has RQ of 0.9?
Answer: Respiratory quotient or respiratory quotient (RQ) is defined as the ratio of the volume of CO₂ evolved to the volume of O₂ consumed in respiration Volume of CO₂ evolved RQ = Volume of O₂ consumed when proteins would be the respiratory substrate then the value of RQ will be 0.9.

Question 7. Conversion of fumaric acid from succinic acid is a dehydrogenation step. Write down the step and the enzyme involved in this conversion. Also write down, how many ATP could be formed from this step?
FAD FADH₂

Answer:

Succinic acid Fumaric acid Succinate dehydrogenase

FADH₂ is responsible for the formation of 2ATP.

Question 8. Write down the equation of breakdown of pyruvic acid in aerobic respiration.
+ + + + + + + —Mitochondrial→ + + +

Answer:

Pyruvic acid 4NAD FAD 2H₂O ADP Pi 3CO₂ 4NADH 4H matrix

+ FADH₂ + ATP

Question 9. Write down the activation phase of glycolysis.
Glucose

Answer:

(6C) ATP Mg++ Hexokinase* ADP Glucose-6-phosphate (6C) phaseOrconsuming Phosphohexose isomerase

Activation Fructose-6-phosphate (6C) Energy ATP Mg++ Phosphofructokinase (PFK)* ADP Fructose-1,6-bisphosphate (6C)

Aldolase

Question 10. Write down the summary of ATP, NADH + H⁺ and FADH₂ synthesis in aerobic respiration.

Answer:

Question 11. Write down the equation of anaerobic respiration which excretes lactic acid as a product and give examples which show this type of respiration.

Answer:

CH₃COCOOH —Lactic acid dehydrogenaseZn+₂ → CH₃CHOHCOOH + Energy FMN, (Pyruvic acid) (Lactic acid)

e.g., Lactic acid bacteria and muscle cells during exercise.

Short Answer Type Questions

Question 12. Observe the following figure and answer the following questions.
E
A B F Inner mitochondrial membrane C D
(a) Label A, B, C, D, E, F.
(b) What is the name of the structure?
Answer: (a) A → 2H⁺, B → F₀, F → F₁, C → ADP, D → Pi, E → ATP
(b) It is the diagrammatic presentation of ATP synthesis in mitochondria.

Question 13. How anaerobes are divided on the availability of oxygen?

Answer:

Depending upon the situation micro-organisms are divided in following catagories :

(i) Obligate anaerobes : Those which cannot use oxygen for growth and are even harmed by it.

(ii) Facultative anaerobes are aerobes which can grow without oxygen.

Question 14. (a) Give the name of any three enzymes of Krebs cycle and their reaction catalysed inside the mitochondria.
(b) When does O₂ act as reactant in respiration?

Answer:

(a) (i) Aconitase

(ii) Succinate thiokinase

(iii) Fumarase

Fe⁺² Aconitase

Succinate Succinyl CoA Succinic acid thiokinase GDP GTP

Fumarase Fumaric acid Malic acid

H₂O

(b) Oxygen it acts as a final acceptor of hydrogen and electrons and results in the formation of H₂O molecule.

Question 15. Write down the difference between fermentation and aerobic respiration.
Fermentation Aerobic respiration

Answer:

1. In fermentation partial degradation 1. In this respiration complete degradation

5. NADH is oxidised to NAD⁺ slowly in 5. Herethe conversionis very vigrous. fermentation.

Question 16. What is the function of zymase?
C₆H₁₂O₆ —→Zymase 2C₂H₅OH + 2CO₂

Answer:

(Glucose)

Thus zymase is responsible for conversion of glucose to ethanol.

Question 17. Various intermediates of the pathway of respiration are precursors of various compounds. Explain it.

Answer:

Various intermediates of the pathway of respiration are precursors of various compounds e.g.,

Long Answer Type Questions

Question 18. Write down the three similarities of alcoholic and lactic acid fermentaion.
Answer: (i) Reducing agent NADH+H⁺ is reoxidised to NAD⁺ in both the processes.
(ii) In both of the types, not much energy is released, < 7% of the energy in glucose is released and not all of it is trapped as high energy bonds of ATP.
(iii) Both the processes are hazardous–either acid or alcohol is produced.
(iv) Net gain is 2ATP from one glucose.

Question 19. (a) Differentiate between photophosphorylation and oxidative phosphorylation.
(b) Write down the name of enzymes that convert pyruvic acid into ethanol during respiration.
(c) Which enzymatic complex is involved in the oxidation of ubiquinol in mitochondria?

Answer:

(a) In photophosphorylation, light energy is utilised for the production of proton gradient while it is the energy of oxidation-reduction utilised for the same purpose.
(b) Pyruvic acid decarboxylase, alcohol dehydrogenase.
(c) Cytochrome bc₁ complex (complex III)