Humber Admissions Practice Test

What is the main purpose of cellular respiration?

1. To synthesize proteins

2. To produce energy from sunlight

3. To generate energy from food

4. To eliminate waste from the cell

The correct answer is: To generate energy from food

The main purpose of cellular respiration is to generate energy from food, which is critical for the functioning of all living organisms. During this process, glucose and other organic molecules are broken down in a series of biochemical reactions. The energy released from these reactions is captured in the form of adenosine triphosphate (ATP), which serves as the primary energy currency of the cell. This energy is essential for various cellular activities, including metabolism, muscle contraction, and maintaining homeostasis. The incorrect options provide different functions that are not the central aim of cellular respiration. While synthesizing proteins is a vital process in the cell, it is primarily related to gene expression and translation rather than energy generation. Similarly, producing energy from sunlight refers to photosynthesis, which occurs in plants and some microorganisms, not in cellular respiration. Lastly, while waste elimination is important for cellular health, it is a separate process not directly associated with energy production.