Question

Which of the following is LEAST likely to be required for a series of metabolic reactions? (A) Triacylglycerol acting as a coenzyme (B) Oxidoreductase enzymes (C) Magnesium acting as a cofactor (D) Transferase enzymes

Short answer

Option (A) Triacylglycerol acting as a coenzyme.

Step-by-step solution

Understand the question

The question is asking which option is least likely to be required for a series of metabolic reactions. This means identifying which option does not typically play a key role in metabolic processes.

Review each option

Go through each of the listed options to see how they relate to metabolic reactions: (A) Triacylglycerol acting as a coenzyme (B) Oxidoreductase enzymes (C) Magnesium acting as a cofactor (D) Transferase enzymes

Analyze Option (A)

Triacylglycerol is a type of lipid (fat) stored in the body. Coenzymes are typically small organic molecules that assist enzymes; common coenzymes are vitamins or derived compounds, not storage fats like triacylglycerol. Thus, triacylglycerol is unlikely to act as a coenzyme.

Analyze Option (B)

Oxidoreductase enzymes are involved in oxidation-reduction reactions, crucial for many metabolic pathways. They are commonly required in metabolism.

Analyze Option (C)

Magnesium is a common cofactor necessary for the activity of numerous enzymes involved in metabolism. It is typically required.

Analyze Option (D)

Transferase enzymes transfer functional groups from one molecule to another and are fundamental in many metabolic reactions.

Identify the least likely option

Based on the analysis, triacylglycerol acting as a coenzyme (Option A) is the least likely requirement for metabolic reactions compared to oxidoreductase enzymes, magnesium as a cofactor, and transferase enzymes.

Key concepts

Coenzymes

Coenzymes are essential components in many biochemical reactions. They are small organic molecules that assist enzymes in facilitating reactions. Most coenzymes are derived from vitamins, such as NAD+ from niacin (vitamin B3) or FAD from riboflavin (vitamin B2). They typically work by binding to the enzyme and helping to transfer chemical groups from one molecule to another. This process is crucial for pathways like cellular respiration. Coenzymes are not permanently attached to enzymes and can be reused multiple times. Examples include NADH, FADH2, and coenzyme A.

Oxidoreductase Enzymes

Oxidoreductase enzymes are specialized enzymes involved in oxidation-reduction reactions, commonly referred to as redox reactions. These reactions involve the transfer of electrons between molecules, which is essential in various metabolic pathways like cellular respiration and photosynthesis. Oxidoreductases play a key role in energy production by facilitating electron transfer from nutrients to molecules like oxygen or other electron acceptors. Examples of oxidoreductase enzymes include dehydrogenases, oxygenases, and reductases. These enzymes are crucial in maintaining the balance of oxidation and reduction in cells.

Metabolic Cofactors

Cofactors are non-protein chemical compounds that bind to enzymes and are essential for their activity. They can be either inorganic ions or complex organic molecules. Inorganic cofactors include metal ions like magnesium, which stabilizes the structures of enzymes and helps in substrate binding. Organic cofactors, also known as coenzymes, assist in enzyme activity by facilitating the transfer of atoms or groups of atoms during the reaction. Cofactors are critical in metabolic reactions because they enable enzymes to perform functions that the amino acid residues of the enzyme alone could not accomplish.

Transferase Enzymes

Transferase enzymes are crucial in metabolic reactions that involve the transfer of functional groups from one molecule to another. They play vital roles in processes such as glycolysis, where a phosphate group is transferred from ATP to glucose to form glucose-6-phosphate. Transferases enable cells to rearrange chemical structures, synthesize new compounds, and manage energy efficiently. Examples of transferase enzymes include kinases, which transfer phosphate groups, and transaminases, which transfer amino groups. These enzymes are indispensable in many biosynthetic and degradation pathways within the cell.