Question

Metabolic reactions that break down complex molecules into smaller compounds, thereby releasing usable energy for the cell, are best described as

Answer 1

Catabolic reactions break down complex molecules, such as carbohydrates, lipids, and proteins, into smaller molecules, releasing energy for cellular use, particularly in the form of ATP.

Step-by-step explanation:

Metabolic reactions that break down complex molecules into smaller compounds, releasing usable energy for the cell, are best characterized as catabolic reactions. These include the degradation of larger molecules like carbohydrates, lipids, and proteins into their smaller components. For example, the process by which glucose is broken down during cellular respiration is a catabolic reaction. This reaction not only breaks down glucose but also releases energy that is essential for the cell to carry out various life processes. The produced energy can be transferred to molecules like ATP (adenosine triphosphate), which acts as the main energy currency in cells, powering various forms of cellular work.

The term metabolism encompasses all of the chemical reactions within a cell, which are divided mainly into two categories: catabolism (breaking down molecules to extract energy) and anabolism (building complex molecules, requiring energy). Catabolic pathways are exergonic as they release energy, which is subsequently harnessed by the cell. About 40 percent of the energy released from catabolic processes is captured in ATP, while the rest is lost as heat. Therefore, catabolic reactions play a crucial role in providing the energy needed for cellular activities, including anabolic processes, which construct complex molecules from simpler ones.

Answer 2

Metabolic reactions that break down complex molecules into smaller compounds, releasing usable energy for the cell, are best described as catabolic reactions. Catabolic processes involve the breakdown of larger molecules (such as carbohydrates, fats, and proteins) into smaller units, releasing energy that can be harnessed by the cell for various biological processes like cellular respiration, ATP production, and other metabolic activities.