Respiration in Plants Test - 15

All living organisms have a common pathway of respiration. EMP (Embden–Meyerhof–Parnas) or glycolysis occurs in the cytosol. In the reaction, one glucose molecule gets converted into two pyruvic acid.

30 moles of ATP are produced from 1 mole of glucose through the Krebs cycle.

Anaerobic respiration is carried out in the absence of oxygen and is also known as fermentation.

The major purpose of this pathway is generation of reduced NADPH and pentose phosphates for nucleotide synthesis. The HMP  pathway has oxidative and non oxidative phases. During the oxidative phase, glucose-6-phosphate is oxidised with the generation of 2 molecules of NADPH, and one molecule of pentose phosphate, with the libration of one molecule of $$CO_2$$. During the non oxidative phase, the pentose phosphate is converted to intermediates of glycolysis.
So, the correct answer is option B.

The metabolic fate of acetyl CoA and acetoacetate is the production of fatty acids or ketone bodies. Amino acids that are metabolized to produce acetyl CoA and acetoacetate are called ketogenic. The fatty acids produce ketone bodies, so they are called ketogenic. Both the glycerol and fatty acid portion of triglycerides can provide energy, fatty acids are the most concentrated source. Fatty acids break down into two carbon fragments to be converted into acetyl CoA. When fatty acids are converted to acetyl CoA, the action is irreversible and they are committed to enter the TCA cycle.

• TCA or Tricarboxylic Acid Cycle or Krebs cycle oxidizes the compounds like acetyl-CoA obtained from carbohydrates, fats, and proteins and leads to the production of carbon dioxide and energy in form of GTP, NADH$$_2$$, and FADH$$_2$$.

• The respiratory quotient is less than one if respiration is aerobic and the respiratory substrate is either fat or protein. 
• Maize contains carbohydrates and groundnut seeds have fatty acids. RQ of carbohydrates is 1.0 and of fats is less than 1. 
• So, the RQ of this mixture would be less than 1. 

Thus, the correct answer is option B.

A.Correct option B
B.Explanation for correct option:

• The respiratory quotient is the ratio, which defines the amount of CO2CO2 eliminated to that of O2O2 consumed. 
• Thus it is evident that it solely depends on the nature of the substrate.
• For example, hexose sugar will have a value of RQ = 1, and fats have an RQ less than one. 
• During the oxidation of carbohydrates, the amount of oxygen used is equal to the amount of carbon dioxide produced.

• Kreb's cycle only produces 1 molecule of ATP from every pyruvate molecule during the conversion of succinyl-CoA to succinate in the presence of enzyme Succinyl CoA synthetase. 
• One molecule of glucose undergoes glycolysis to produce 2 pyruvate molecules which enter Kreb's cycle simultaneously.
• Thus, overall 2 ATP are produced from Kreb's cycle through substrate-level phosphorylation when one glucose undergoes aerobic respiration.