MCQ on Cellular Respiration

Cellular respiration, the aerobic process in which living cells break down glucose molecules in order to release energy for the production of ATP molecules is defined as follows: The reaction between oxygen and glucose occurs in three phases, resulting in the formation of water and carbon dioxide. This mechanism causes the chemical energy contained in such substances to be channelled into actions that support life and the elimination of wastes, rather than being wasted.

1. Carbon dioxide generated during cellular respiration is

(a) assimilated

(b) removed from consideration

(c) it is kept on hand

(d) was ingested

Answer : (b) When cells respire, carbon dioxide is released as a waste product, and this is known as cellular respiration. Photosynthesizing cells can utilise this carbon dioxide to produce new carbohydrates, which is beneficial to the environment.

2. The reduction of NADP⁺ to NADPH occurs.

(a) HMP is an abbreviation for High-Motion Picture

(b) Calvin Cycle

(c) Glycolysis

(d) EMP (1988)

 Answer: a) When NADPH molecules are not created by photosynthesis, the HMP pathway creates NADPH molecules, which are employed as reductants in the biosynthetic process.  In non-photosynthetic tissues such as differentiating tissues, seed production, and during times of darkness, it is consequently essential. There is no connection between the production of NADPH and the generation of ATP in the pentose phosphate pathway.

3. Glycolysis produces a final product.

(A) Acetyl CoA

(B) Pyruvic acid

(C) Glucose I-phosphate

(D) Fructose I-phosphate.

Answer: (B)

When glucose (a hexose sugar) enters the glycolytic cycle, it undergoes a series of metabolic events controlled by enzymes that result in the formation of two molecules of pyruvic acids for each molecule of glucose. The cytosol is where the action takes place.

4. EMP has the capability to producing a total of

(A) 6 ATP

(B) 8 ATP

(C) 24 ATP

(D) 38 ATP.

Answer: (B) 

Glycolysis is often referred to as the EMP route, after the names of the researchers that discovered it. Embden, Meyerhof, and Piranhas are three of the best. During glycolysis, eight ATP molecules are created. Substrate-level phosphorylation generates 4ATP; out of this, two are spent up and the remaining two are gained, yielding a net gain of two AT P. 6ATP is generated as a result of oxidative phosphorylation. As a result, the total amount of ATP created during glycolysis is 8ATP.

5. Changes are made to the connecting connection between glycolysis and the Krebs cycle before pyruvate enters the Krebs cycle.

(A) Oxaloacetate

(B) PEP

(C) Pyruvate

(D) Acetyl CoA.

Answer: (D) 

A by-product of glycolysis is pyruvic acid, which is then transformed into acetyl coA before joining the Krebs cycle, which is an aerobic cycle seen in the natural world.

6. The cytochrome c of the respiratory chain’s terminal cytochrome, which provides electrons to oxygen is

(A) Cyt. b

(B) Cyt. c

(c) Cyt. A1

(D) Cyt. a3.

Answer: (D)

The transport of electrons from hydrogen to oxygen is aided by cytochrome a3. The oxygen atom has a high affinity for accepting electrons, and when combined with protons, this results in the formation of a water molecule.

7. During respiration, a total of 36 ATP molecules are created for every glucose molecule.

(A) Two metabolites are created outside of glycolysis, and 34 metabolites are produced during the respiratory chain

(B) Two are created outside mitochondria while thirty-four are produced inside mitochondria.

(C)During glycolysis, there are two electrons, and there are 34 during the Krebs cycle.

(D) They are all created within mitochondria.

Answer: (B)

During the process of respiration, 36 ATP molecules are created for every glucose molecule consumed. Two molecules of ATP are produced outside of the mitochondria, during glycolysis, while the remaining thirty-four molecules of ATP are produced inside the mitochondria, during the Krebs cycle .

8. The link between glycolysis, the Krebs cycle, and P-oxidation of fatty acids or carbohydrates and fat metabolism is known as the Krebs cycle.

(A) Oxaloacetic acid

(B) Succinic acid

(C) Citric acid

(D) Acetyl CoA.

Answer: (D)

The Krebs cycle is directly linked to the process of fat metabolism. It is possible to transform the dihydroxyacetone phosphate produced during glycolysis into glycerol and vice versa by the use of glycerol — 3 — phosphate. Glycerol is one of the most significant components of fats. Following P-oxidation, fatty acids produce active — 2 — C units, such as acetyl-CoA, which can then be used to join the Krebs cycle. Acyl-CoA serves as a link between glycolysis, the Krebs cycle, P-oxidation of fatty acids or carbohydrate metabolism, and fat metabolism as a result.

9. The end products of aerobic respiration are as follows:

(A) Sugar and oxygen

(B) Water and energy

(C) Carbon dioxide, water and energy

(D) Carbon dioxide and energy.

Answer: (c)

A process known as aerobic respiration occurs in which the dietary molecules in living cells are oxidised in the presence of oxygen. The complete oxidation of dietary materials (1. mole of glucose) occurs, releasing 686 Kcal of energy into the atmosphere. CO2 and H2O are the by-products of the formation process.

10. When the temperature rises above 35°C

(A) The rate of photosynthesis will fall sooner than the rate of respiration will decline.

(B) The rate of respiration will begin to fall before the rate of photosynthesis does.

(C)There is no set pattern to follow.

(D) Both parties experience a deterioration at the same time.

Answer: (A)

Plants can perform photosynthesis at a variety of temperatures, with certain cryophytes capable of performing photosynthesis at temperatures as low as 35°C. Normally, plants can undertake photosynthesis at temperatures ranging from 10°C to 40°C. Temperatures between 25°C and 30°C are ideal for this process. Due to the denaturant of the enzymes caused by high temperatures, the photosynthetic rate decreases significantly.

11.The process of oxidative phosphorylation is the generation of

(A) ATP in photosynthesis

(B) NADPH in photosynthesis

(C) ATP in respiration

(D) NADH in respiration.

Answer: (c)

FAD, which is converted to FADH₂, accepts the hydrogen provided by succinate and transports it through the electron transport system. It then goes through a series of carriers including the phenomena of oxidation and reduction before dissociating into electrons and protons again to return to its original state. Oxidative phosphorylation is a term used to describe the process by which ATP is synthesised at different stages during this flow.