Botany MCQs for NEET — Practice Questions with Answers

In aerobic respiration, the respiratory substrate (like glucose) is completely oxidised to carbon dioxide and water, releasing a significant amount of energy. This process occurs in the presence of oxygen.

Aerobic respiration releases more energy compared to anaerobic respiration because it involves the complete oxidation of glucose. This process yields about 36-38 ATP molecules per glucose molecule, whereas anaerobic respiration yields only about 2 ATP molecules per glucose molecule.

Fermentation occurs in the absence of oxygen. It is an anaerobic process that allows cells to produce energy without oxygen, typically resulting in the production of alcohol or lactic acid.

The first stage in respiration is Glycolysis. Glycolysis is the process in which one molecule of glucose is broken down into two molecules of pyruvic acid. This process takes place in the cytoplasm of the cell and does not require oxygen, making it an anaerobic process.

During glycolysis, one molecule of glucose (which is a 6-carbon compound) is split into two molecules of pyruvic acid (each a 3-carbon compound). Therefore, the number of pyruvic acid molecules formed in glycolysis is 2.

Pyruvic acid, also known as pyruvate, is a 3-carbon molecule. It is the end product of glycolysis, where one glucose molecule is split into two pyruvic acid molecules, each containing three carbon atoms.

Glycolysis is the first step in the breakdown of glucose to extract energy for cellular metabolism. It occurs in the cytoplasm of the cell. This process does not require any organelles and takes place in the cytosol, which is the liquid part of the cytoplasm.

ADP (Adenosine Diphosphate) combines with inorganic phosphate (Pi) to form ATP (Adenosine Triphosphate). This process is known as phosphorylation and is crucial for storing and transferring energy in cells.

Dihydroxyacetone phosphate (DHAP) is a 3-carbon (3C) compound. It is an intermediate in glycolysis and is formed from the splitting of fructose 1,6-bisphosphate.

In the glycolysis pathway, a total of 2 ATP molecules are consumed during the initial steps. Specifically, one ATP is used to phosphorylate glucose to glucose-6-phosphate, and another ATP is used to convert fructose-6-phosphate to fructose-1,6-bisphosphate.