NEET Practice Questions (MCQs) with Answers & Solutions

During respiration, pyruvic acid is broken down into a two-carbon fragment (Acetyl-CoA) and carbon dioxide (CO₂). This process is a part of the link reaction or transition stage before entering the Krebs cycle.

Palmitic acid, a type of fatty acid, undergoes beta-oxidation which produces a significant amount of ATP. During the complete oxidation of one molecule of palmitic acid, a total of 129 ATP molecules can be synthesized. This is higher compared to glucose and other mentioned options.

NADP⁺ is reduced to NADPH in the Hexose Monophosphate Pathway (HMP), also known as the Pentose Phosphate Pathway. This pathway is crucial for producing NADPH, which is essential for biosynthetic reactions and for maintaining the reducing environment of the cell.

Stored food is the source of respiration. During cellular respiration, stored food substances such as carbohydrates, fats, and proteins are broken down to produce ATP, which is the energy currency of the cell.

The raw materials for respiration are glucose and oxygen (O2). During cellular respiration, glucose ( ext{C}6 ext{H}{12} ext{O}_6) is broken down in the presence of oxygen to produce carbon dioxide ( ext{CO}_2), water ( ext{H}_2 ext{O}), and energy (ATP). The balanced chemical equation for this process is: \[ ext{C}_6 ext{H}_{12} ext{O}_6 + 6 ext{O}_2 ightarrow 6 ext{CO}_2 + 6 ext{H}_2 ext{O} + ext{energy (ATP)} \] Thus, glucose and oxygen are the raw materials for respiration.

Respiration is a fundamental process that occurs in all living cells to generate energy. It takes place both in the presence of light and in the dark. Unlike photosynthesis, which occurs only in the presence of light and primarily in green cells, respiration occurs in all types of cells (both green and non-green) and does not depend on light. Thus, respiration is found in all living cells both in light and dark.

Anaerobic respiration is a type of respiration that occurs without the presence of oxygen. It is called intra-molecular respiration because the organic substrate (such as glucose) is partially oxidized within the cell to produce energy. This process usually results in the formation of lactic acid or ethanol and carbon dioxide as end products. In contrast to aerobic respiration, which completely oxidizes glucose to produce more energy, anaerobic respiration yields less energy.

In anaerobic respiration, glycolysis is the primary pathway that occurs, which results in a net gain of 2 ATP molecules per glucose molecule. Therefore, the total gain of energy in anaerobic respiration from one glucose molecule is two ATP.

In cellular respiration, the final electron acceptor is oxygen. Oxygen accepts electrons at the end of the electron transport chain, which allows for the production of water and the continuation of the process of oxidative phosphorylation.

Oxidative phosphorylation occurs in the mitochondria. It is a part of the electron transport chain where ATP is synthesized as electrons are transferred from electron donors to oxygen through a series of protein complexes.