Dental Admissions Test (DAT) Practice Test

Where are ATP molecules primarily produced during cellular respiration in prokaryotes?

1. Mitochondria

2. Nucleus

3. Smooth endoplasmic reticulum

4. Stroma

The correct answer is: Mitochondria

The correct answer highlights that in prokaryotes, ATP molecules are primarily produced in the cytoplasm since they lack membrane-bound organelles like mitochondria. Prokaryotic cells, which include bacteria, perform cellular respiration through a series of reactions that occur in their cytoplasmic membrane and the surrounding cytoplasm. The electron transport chain, which is crucial for ATP production, is located within the cell membrane, allowing prokaryotes to generate ATP through processes such as oxidative phosphorylation. The other options represent structures not involved in ATP production in prokaryotes. Mitochondria are indeed the sites of ATP production in eukaryotic cells but do not exist in prokaryotes. The nucleus is primarily responsible for housing genetic material and does not partake in ATP production. The smooth endoplasmic reticulum plays roles in lipid synthesis and detoxification without being directly involved in ATP generation, while the stroma is part of chloroplasts in plant cells, which are involved in photosynthesis rather than cellular respiration in prokaryotes.