Florida Teacher Certification Examinations (FTCE) Subject Area Practice Test

Where does the primary production of energy in cells occur?

1. Nucleus

2. Ribosome

3. Mitochondria

4. Cytoplasm

The correct answer is: Mitochondria

The primary production of energy in cells occurs in the mitochondria. These organelles are often referred to as the "powerhouses" of the cell because they are the site of cellular respiration, the process by which glucose and other organic molecules are converted into adenosine triphosphate (ATP), the energy currency of the cell. Mitochondria have their own DNA and a specialized double membrane that facilitates this energy conversion process. During cellular respiration, glucose is broken down in a series of complex reactions that occur in different parts of the mitochondria. The inner membrane is where the electron transport chain operates, producing ATP through oxidative phosphorylation. The efficiency of this process allows cells to generate the energy needed for various cellular functions, making mitochondria essential for the survival and functioning of aerobic organisms. Other options, such as the nucleus and ribosomes, play crucial roles in cellular processes, but they are not directly involved in energy production. The nucleus is primarily responsible for regulating gene expression and storing genetic information, while ribosomes are the sites of protein synthesis. The cytoplasm contains metabolic pathways that can contribute to energy production but does not perform the primary energy conversion like the mitochondria do.