Western Governors University (WGU) BIO1010 C190 Introduction to Biology Practice Exam

The process of cellular respiration primarily converts glucose into ATP. During this metabolic pathway, glucose undergoes a series of reactions, starting with glycolysis, followed by the Krebs cycle (or citric acid cycle), and concluding with the electron transport chain. These stages serve to break down glucose, releasing energy that is captured in the form of ATP, which is the energy currency of the cell.

While carbohydrates can also be involved in this process, glucose is the simplest form and serves as a direct substrate for the initial steps of cellular respiration. Proteins and fats can be metabolized to produce ATP, but this typically occurs through conversions into intermediate molecules that can enter the pathways used for glucose metabolism. Therefore, glucose is uniquely positioned as the primary molecule directly converted into ATP during cellular respiration, making it the correct answer.