What is the role of mitochondria in cells?

Mitochondria are often referred to as the "powerhouses" of the cell due to their crucial role in energy production. They are the sites of cellular respiration, a process that converts biochemical energy from nutrients into adenosine triphosphate (ATP), which is the energy currency of the cell. This process involves the breakdown of glucose and other substrates in the presence of oxygen, resulting in the release of energy, carbon dioxide, and water.

In this context, the correct answer highlights the essential function of mitochondria in generating ATP, which is vital for powering various cellular activities, from muscle contraction to nerve impulse transmission. By converting food into energy, mitochondria enable cells to carry out their functions effectively.

The other options pertain to different cellular functions: protein synthesis occurs primarily in ribosomes, genetic information is stored in the nucleus within DNA, and transport within the cell is managed by the endoplasmic reticulum and vesicles. Each of these processes is critical, but they are distinctly separate from the energy-producing role of mitochondria. Understanding the function of mitochondria provides insight into how cells obtain and utilize energy, a fundamental aspect of biology.