NEET Practice Questions (MCQs) with Answers & Solutions

The conversion of pyruvic acid into ethyl alcohol (ethanol) involves two enzymes: decarboxylase and dehydrogenase. Decarboxylase removes a carboxyl group from pyruvic acid to form acetaldehyde, and dehydrogenase reduces acetaldehyde to ethanol.

The Respiratory Quotient (RQ) for fats is typically less than one. This is because fats require more oxygen for their oxidation compared to the amount of carbon dioxide they produce. The RQ value is calculated as the ratio of CO2 produced to O2 consumed. For fats, this value is usually around 0.7.

The Respiratory Quotient (RQ) for glucose is 1. This is because the complete oxidation of glucose produces an equal amount of carbon dioxide (CO2) and consumes an equal amount of oxygen (O2). The RQ value is calculated as the ratio of CO2 produced to O2 consumed, and for glucose, this ratio is 1.

Phosphorus plays an indispensable role in energy metabolism. It is a key component of ATP (adenosine triphosphate), which is the primary energy carrier in cells. ATP is essential for various biological processes, including muscle contraction, nerve impulse propagation, and chemical synthesis.

Glucose is considered the instantaneous source of energy because it is the primary fuel used by cells for quick energy production. When glucose is broken down during cellular respiration, it rapidly produces ATP, which is the energy currency of the cell.

The conversion of pyruvate to acetyl CoA involves oxidative decarboxylation. In this process, pyruvate undergoes decarboxylation to release a molecule of CO₂ and is oxidized to form acetyl CoA, which enters the Krebs cycle for further energy production.

During ATP synthesis, electrons pass through a series of protein complexes known as cytochromes in the electron transport chain. These cytochromes facilitate the transfer of electrons, ultimately leading to the production of ATP.

NAD (Nicotinamide adenine dinucleotide) is a universal hydrogen acceptor. It plays a crucial role in cellular respiration and metabolic processes by accepting electrons and hydrogen ions to form NADH.

In plants, energy is primarily produced during the process of respiration. During respiration, glucose is broken down with the help of oxygen to release energy in the form of ATP.