AST Surgical Technologist Practice Exam

Which organelle is primarily responsible for producing energy in the cell?

1. Nucleus

2. Mitochondria

3. Ribosome

4. Lysosome

The correct answer is: Mitochondria

The mitochondria are often referred to as the "powerhouses" of the cell because they are primarily responsible for producing adenosine triphosphate (ATP), the energy currency of the cell. This process occurs through cellular respiration, where nutrients are converted into energy. The inner membrane of mitochondria hosts protein complexes that play a key role in the electron transport chain, facilitating the production of ATP. Mitochondria also contain their own DNA and ribosomes, which allows them to replicate independently and produce some of the proteins needed for their energy-generating functions. In contrast, the nucleus is the control center of the cell, housing genetic material and coordinating activities such as growth and reproduction. Ribosomes are involved in protein synthesis rather than energy production, and lysosomes are responsible for breaking down waste materials and cellular debris. Thus, the primary role of mitochondria in energy production distinguishes them as the organelle responsible for generating the energy that powers various cellular functions.