MCQ on Respiration in Plants

MCQ on Respiration in Plants MCQ on Respiration in Plants

1. Which one of the following reactions is an example of oxidative Decarboxylation?
   a) Conversion of succinate to fumarate
   b) Conversion of fumarate to malate
   c) Conversion of pyruvate to acetyl Co-A
   d) Conversion of citrate to isocitrate

2. If O₂ is not present, yeast cells break down glucose to
a) CO₂+H₂O
b) CO₂+ Lactic acid
c) C₂ H₅ OH+H₂O
d) C₂ H₅ OH and CO₂

3. How many ATP is released respectively when NADH and FADH₂ molecules get oxidized?

a) 3 ATP, 2 ATP 
b) 2 ATP, 3 ATP 
c) 5 ATP, 4 ATP 
d) 3 ATP, 5 ATP

4. Release of energy by breaking down of C-C bond of various organic molecules by oxidation process for cellular use is known as

a) Respiration   
b) Photorespiration
c) Oxidative phosphorylation     
d) Combustion

5. Krebs’ cycle was discovered by Krebs in pigeon muscles in 1940. Which step is called gateway step/link reaction/transition reaction in respiration?

a) Glycolysis      
b) Formation of acetyl Co-A
c) Citric acid formation  
d) ETS terminal oxidation

6. Correct sequence of electron acceptor of ATP synthesis is

a) cyt-a, a_3 , b, c            
b) cyt-b, c ,a, a_3             
c) cyt-b, c , a_3, a             
d) cyt-c, b, a, a_3

7. The number of ATP produced when a molecule of glucose undergoes fermentation

a) 4        
b) 36     
c) 2        
d) 38

8. Oxidative decarboxylation is

a) Pyruvic acid is oxidized to carbon dioxide        
b) Pyruvic acid is subsidized to oxygen
c) Pyruvic acid is oxidized to oxygen       
d) Pyruvic acid is subsidized to carbon dioxide

9. An example of Pasteur’s effect is

a) Penicillium    
b) Pinnularia      
c) Saccharomyces           
d) Nostoc

10. Fermentation is

a) Anaerobic respiration
b) Incomplete oxidation of carbohydrate
c) Complete oxidation of carbohydrate  
d) None of the above

11. Citric acid cycle is the alternate name of which of the following?

a) HMP shunt    
b) Glycolysis      
c) TCA cycle       
d) Calvin cycle

12. When one molecule of glucose is completely oxidized during aerobic respiration, how many molecules of carbon dioxide are released due to Tricarboxylic acid cycle?

a) One  
b) Two
c) Three              
d) Four

13. Fat prior to its oxidation associate with

a) Cyclic AMP    
b) Co-A
c) GMP
d) ATP

14. The RQ value of oxalic acid is

a) 1.0    
b) 0.7    
c) 4        
d) ∝

15. Energy currency of cell is

a) Mitochondria
b) Chloroplast   
c) ATP  
d) Glucose

16. Break down process is also called

a) Catabolism    
b) Anabolism    
c) Both (a) and (b)           
d) All of these

17. The energy-releasing metabolic process in which substrate is oxidized without an external electron acceptor, is called

a) glycolysis       
b) Fermentation              
c) Aerobic respiration    
d) Photorespiration

18. How many times ATP is utilised in glycolysis?

a) 2        
b) 3       
c) 4        
d) 5

19. Aerobic respiration takes place in

a) Mitochondria
b) Ribosome     
c) Glogi body     
d) Both (a) and (b)

20. Sequence of events in Kreb’s cycle is

a) Acetyl Co-A → Citrate → Pyruvate → Oxaloacetic acid ← fumarate ← Malate ← Succinate α-ketoglutaralte

b) Acetyl Co-A → Citric acid → α-ketoglutarate acid → Oxaloacetic acid ← Malic acid ← Fumaric acid ← Succinic acid

c) Acetyl Co-A → Citric acid → Malic acid Oxaloacetic ← Oxaloacetic acid Succinic ← α-ketoglutaric acid ←

d) All are wrong

1 (b)

2              (b)

In anaerobic respiration, i.e., absence of O₂, glycolysis and fermentation involve. In fermentation incomplete oxidation of glucose is processed by sets of reaction where pyruvic acid is converted to CO₂ and ethanol

3              (a)

It is well known fact that photosynthesis in eukarytoes occurs in chloroplast whereas in prokaryotes it is in cytoplasm

4              (c)

Anaerobic respiration occurs in absence of oxygen. It is found in deep-seated tissues of plants and animals, germinating seeds, yeasts and bacteria. During anaerobic respiration of yeast, two ATP produced from each glucose molecule. Hence, 38 ATP will produce from 19 glucose molecules.

5              (b)

In aerobic respiration, glycolysis is linked with Krebs’ cycle through acetyl Co-A because pyruvic acid (end-product of glycolysis) first converted into acetyl Co-A. The acetyl Co-A enters in the Krebs’ cycle. The formation of acetyl Co-A is involved with some cofactors like Mg ions, thiamine pyrophosphate (Vitamin-B₁), NAD⁺ , Co-A and lipoic acid. 

6 (d)

In anaerobic respiration CO₂ is evolved but oxygen is not used. Therefore in such case respiratory quotient will be infinite. e.g.,

Where Respiratory Quotient

7              (c)

The NADH synthesised in glycolysis is transferred into the mitochondria and undergoes oxidative phosphorylation

8              (b)

Total gain of 38 ATP molecules during aerobic respiration of one molecule of glucose

9              (a)

During glycolysis, in the presence of enzyme Hexokinase, glucose is converted into glucose-6-phosphate by using one ATP molecule in presence of Mg2⁺

10           (b)

In the presence of Zymase, alcoholic fermentation takes place.

11           (c)

During the conversion of Succinyl Co-A to Succinic acid, a molecule of GTP is synthesized. This is a substrate level phosphorylation. In a coupled reaction, GTP is converted to GDP with the simultaneous synthesis of ATP from ADP.

12           (b)

Pyruvic acid is 3C-compound. One of the three carbon atoms of pyruvic acid is oxidised to carbon dioxide in a reaction called oxidative decarboxylation. Pyruvate is first decarboxylated and then oxidised by the enzyme pyruvate dehydrogenase. The combination of the remaining 2-carbon acetate unit is readily accepted by a sulphur containing compound, coenzyme A (Co-A) to form acetyl Co-A

13 (b)

Co- A

The respiratory decomposition of fatty acids is known as beta oxidation, which occurs in liver and adipose tissue. Activation of fatty acids takes place, then dehydrogenation of activated fatty acid takes place. It is followed by hydration. The β-hydroxyl acyl derivative is converted to β-keto derivative, which then reacts with Co-A. And it leads to oxidation.

14           (c)

Generally lower organism, e.g., bacteria and fungi performs anaerobic respiration but also occur in higher organism

15           (b)

Pathway – A is glycolysis ⟶2 NADH+H^-

Pathway – B is Kreb’s cycle ⟶6 NADH+H⁺

Pathway – C is Electron transport system

Between pathway A and pathway B ⟶2 NADH+H⁺ produced

16           (a)

In electron transport chain respiratory process are to release and utilise the energy stored in NADH ⁺ H⁺ and FADH₂. This is accomplished when they are oxidised through the electron transport system and the electron are passed on to O₂ resulting in the formation of H₂O

17           (b)

During citric acid cycle, 3 molecules of NAD⁺ and one molecule of FAD (Flavin Adenine Dinucleotide) are reduced to produce NADH and FADH₂ respectively. These reduced electron carriers pass on the hydrogen atoms to oxygen through electron transport system, yielding II more ATP molecules for each molecule of pyruvic acid.

In addition one ATP molecules is generated directly during the cycle to give a total of 12 ATP molecule per pyruvic acid molecules. As two molecules of pyruvic acid are produced from each molecule of glucose a total of 24 molecules of ATP are formed during the citric acid cycle

18           (d)

When the fats respire, the value of RQ is less than one.

19           (d)

Glycolysis involves ten step for each step, specific enzyme needs to go next step

20           (d)

ATP is a coenzyme. Coenzyme is an organic cofactor molecule smaller than protein that bonds with a specific enzyme, while the reaction is being catalysed.