Respiration in Plants – AIIMS AIPMT PMT NEET JIPMER MCAT Questions

l. Multiple Choice Questions Identify the enzymes 1 and 2 in the given reaction and select the correct option.




(a) Ethanol dehydrogenase Pyruvate decarboxylase
(b) Ethanol decarboxylase Pyruvate dehydrogenase
(c) Pyruvate decarboxylase Alcohol dehydrogenase
(d) Pyruvate dehydrogenase Ethanol dehydrogenase
2. What does A, B and C depict in the given pathways of anaerobic respiration?












3. When two molecules of acetyl-CoA enter the TCA cycle, net gain at the end of the cycle is
(a) 2NADH2 + 2FADH2 + 1GTP
(b) 3NADH2 + 2FADH2 + 2GTP
(c) 6NADH2 + 2FADH2 + 2GTP
(d) 3NADH2 + 1FADH2 + 4GTP.
4. The first 5-C dicarboxylic acid in Krebs’ cycle which is used in nitrogen metabolism is
(a) OAA
(b) citric acid
(c) a-ketoglutaric acid
(d) acetyl coenzyme A.
5. Which of the following steps is associated with ATP formation (substrate level phosphorylation)?
(a) Succinyl CoA Succinic acid
(b) 1,3 bisPGA –>3 PGA
(c) PEP Pyruvate
(d) All of these
6. Which of the following are isomers?
(a) 3PGA and 2PGA
(b) PGAL and DiHAP
(c) Glucose and Fructose
(d) All of these
7. Select the correct sequence of formation of given intermediates of Krebs’ cycle.
(a) Succinate Malate Fumarate -»OAA
(b) Fumarate -»Succinate -> Malate -»OAA
(c) Succinate Fumarate -» Malate —> OAA
(d) Malate —> Fumarate -»Succinate —> OAA
8. At the end of glycolysis, X is the net energy gain from one molecule of glucose via X but there is also energy stored in the form of Z. Identify X, Y and Z.

(a) 1 ATP Oxidative
(b) 2 ATP Oxidative
(c) 1 ATP Substrate level phosphorylation FADH2
(d) 2 ATP Substrate level phosphorylation NADH + H+

9. In the electron transport system present in the inner mitochondrial membrane, complexes I and IV respectively are
(a) NADH dehydrogenase and FADH2
(b) FADH, and NADH dehydrogenase
(c) NADH dehydrogenase and cytochrome c oxidase complex
(d) NADH dehydrogenase and ATP synthase.
10. In respiration from 180g of glucose which of the following is formed ?
(a) 264gm CO2 + 190gm H2O + 391 Kcal
(b) 264gm CO2 + 108gm H2O+ 686 Kcal
(c) 390gm CO2 + 108gm H2O + 686 Kcal
(d) 390gm CO2 + 264gm H2O + 391 Kcal
11. Rise in the water level from X to Y in the given experimental set-up demonstrates






(a) aerobic respiration
(b) anaerobic respiration
(c) photosynthesis
(d) transpiration pull.
12. The respiratory quotient (R.Q.) of some of the compounds are 4, 1 and 0.7. These compounds are identified respectively as
(a) malic acid, palmitic acid and tripalmitin
(b) oxalic acid, carbohydrate and tripalmitin
(c) tripalmitin, malic acid and carbohydrate
(d) palmitic acid, carbohydrate and oxalic acid.
13. Given below the diagrammatic presentation of ATP synthesis in mitochondria. Identify A-C and choose the correct option accordingly.






(a) A – H+, B – F1, C – F0
(b) A – 3H+, B – F0, C  -F1
(c) A – 2H+, B – F0, C – F1
(d) A – 5H+, B – F1, C- F8

14. In oxidative photophosphorylation, the last 3 steps are as follows:
CoQ Cyt c Cyt a a3 -> O2
(a) CoQ Cyf c is H+ absorbing site
(b) Cyt a a3 > O2, H+ yielding site
(c) CoQ -» Cyt c is H+ yielding site and Cyt a a3 -> O2 is H+ absorbing site
(d) no H+ is absorbed or released
15. The TCA cycle is an oxidative pathway requiring oxygen for operation. The enzyme which consumes oxygen during the operation of the cycle is
(a) a-ketoglutarate dehydrogenase
(b) isocitrate dehydrogenase
(c) aconitase
(d) none of the above.
True or False
16. Succulents evolve carbondioxide at night as their stomata open only at night.
17. Four molecules of NADH2 are formed in total at the time of oxidation of glyceraldehyde 3-phosphate to 1 :3 bisphosphoglycerate.
18. Energy released during passage of electrons from one carrier to the next is made available to specific transmembrane complexes, which pump protons from the outer chamber of mitochondria to the matrix.
19. Since, one ATP molecules stores 34 KJ or 8.15 Kcal/ mole, the total energy trapped per gm mole of glucose is 1292 KJ or 309.7 Kcal with an efficiency of only 45%, and the rest of energy is lost as heat.
20. Anaerobic respiration or fermentation in yeast in a sugary solution results in ethyl alcohol which accumulates in its body.
21. The two molecules of pyruvate are degraded in Krebs’ cycle to form 4 ATP, 10 NADH2 and 2 FADH2.
22. Cytochrome c oxidase complex contains cytochrome a3 and cytochrome a, which helps in transfer of electrons to oxygen.
23. Carbon dioxide is not evolved during glycolysis, and is evolved only in Krebs’ cycle.
24. In ATP, only the last two phosphate radicals are attached by bonds of high transfer potential.
25. Electron transport chain is absent in anaerobes and there is no ATP formation during regeneration of NAD+.

Match The Columns

26. Match Column-1 with Column-ll and select the correct option from the codes given below.

Column-I Column-II
A Citrate (i) Aldolase
B Oxaloacetate (ii) Mutase
C PGAL (iii) NADH-Q reductase
D Phosphoglycerate (iv) ATP synthase
E PEP (v) Kinase
F Complex V (vi) Malate dehydrogenase
G Compex I (vii) Aconitase

27. Match Column-1 with Column-ll and select correct options from codes given below. There can be more than one match for items in Column-1.

Column-I Column-II
A  Elementary particle (i)  FD
B  Fermentation (ii)  Lactic dehydrogenase
 C  Cytochrome c oxidase  (iii)  Cytochrome a
 D  Oxaloacetate  (iv)  Pyrimidine
 E  Fructose 1 :6 bisphosphate  (v)  GAP
 F  Floating respiration  (vi)  Alcohol dehydrogenase
 G  Protoplasmic respiration  (vii)  Carbohydrates
 (viii)  R.Q.: 0.9
 (ix)  F1
(x) Fats
(xi) DiHAP
(xii) Alkaloid
(xiii) Cytochrome a3
(xiv) Proteins

Passage Based Questions
28.(A) Complete the given passage with appropriate words or phrases.
Pyruvate enters mitochondria and undergoes (i) to produce (ii) and (iii). The product combines with (iv) containing (v) to form (vi). in the presence of (vii) This step is called (viii).
(B) Read the passage and correct the errors, wherever present.
Higher proton concentration in the inner chamber causes the protons to pass outwardly into matrix. The flow of protons through F1 channel induces F0 particle to function as ATP.
Assertion & Reason
In each of the following questions, a statement of Assertion is given and a corresponding statement of Reason is given just below it. Of the statements, mark the correct answer as:
(a) if both A and R are true and R is the correct explanation of A
(b) if both A and R are true but R is not the correct explanation of A
(c) if A is true but R is false
(d) if both A and R are false.
29. Assertion: Respiratory quotient is infinity in anaerobic respiration as there is no consumption of oxygen. Reason : An intermediate value is obtained where an organ is undergoing both aerobic and anaerobic modes of respiration.
30. Assertion: Citrate undergoes reorganization in the presence of copper containing enzyme aconitate, forming isocitrate and releasing water.
Reason: Isocitrate is then converted into cis-aconitate with removal of water, while attached to enzyme aconitase.
31. Assertion : Terminal oxidation occurs in aerobic respiration at the end of catabolic process.
Reason : It involves the passage of only electrons to oxygen producing water.
32. Assertion: The difference in the proton concentration on the outer and inner sides of the outer mitochondrial membrane creates an electric potential across the membrane.
Reason : The outer surface becomes negative as compared to inner surface.
33. Assertion : Plants have no specialised respiratory organs.
Reason : There is very little transport of gases from one plant part to another.
34. Assertion : Substrate level phosphorylation is directly linked to liberation of energy in chemical reaction of respiration.
Reason : It occurs only in Krebs’ cycle.
35. Assertion : During strenuous exercise, lactic acid is produced from pyruvic acid in skeletal cells, as a result of anaerobic respiration.
Reason : The lactic acid is excreted out through digestive and urinary tract.
36. Assertion : Ensilage or preserved fodder is prepared by keeping green chopped fodder in silos.
Reason : Bacterial action and their anaerobic fermentation causes softening and release of preserving acids.
37. Assertion : The bond between second and third phosphate radicals possesses an energy equivalent of 6.5 Kcal/mole.
Reason : The bond linking second phosphate radical with the first one has an energy equivalent of 8.15 Kcal/mole.
38. Assertion : QH2-cytochome c reductase complex has three components-cytochrome b, FeS complex and cytochrome cy
Reason : Coenzyme Q is belived to be involved between FeS complex and cytochrome c1.
Figure Based Questions

39. Refer to the figure below and identify the labelled parts – P, Q, R, S and T.


















40. Fill in the blanks using the given letters / appropriate words.
(a) Substrate level phosphorylation occurs between (i) and (ii) . It also occurs between (iii) and (iv)
(b) Oxidation and phosphorylation occurs between (v) and (vi).


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