Botany MCQs for NEET — Practice Questions with Answers

Oxidative phosphorylation occurs in the cristae of the mitochondria. The electron transport chain and ATP synthase are located on the inner mitochondrial membrane, which is folded into cristae to increase the surface area for this process.

Malic acid is formed from fumaric acid by the addition of a water molecule (H2O). This hydration reaction is catalyzed by the enzyme fumarase in the citric acid cycle (Krebs cycle).

One ATP (or GTP, depending on the cell type) is formed during the conversion of Succinyl CoA to Succinic acid in the Kreb’s cycle. This step involves substrate-level phosphorylation where GDP is converted to GTP, which can then be converted to ATP.

The respiratory quotient (RQ) is the ratio of CO2 produced to O2 consumed. An RQ of 0.7 typically indicates that fats are being metabolized, as fats require more oxygen for respiration compared to carbohydrates. Therefore, if RQ is 0.7, the substance needs more O2 for respiration.

The Pentose Phosphate Pathway (PPP) occurs in the cytosol of the cell. This pathway is crucial for the production of NADPH and ribose-5-phosphate, which are essential for anabolic reactions and nucleic acid synthesis, respectively.

When human muscles contract and there is insufficient oxygen supply, anaerobic respiration occurs. This process converts glucose to lactic acid, which can cause muscle fatigue and soreness. This is an adaptive mechanism to provide energy under low oxygen conditions.

The Krebs cycle, also known as the citric acid cycle, takes place in the mitochondria of cells. Mitochondria are often referred to as the powerhouses of the cell because they generate most of the cell's supply of ATP, which is used as a source of chemical energy.