MoCA Science Practice Test

Cellular respiration is the process through which cells convert glucose and oxygen into energy (in the form of adenosine triphosphate or ATP), carbon dioxide, and water. This biochemical pathway is fundamental to cellular metabolism and occurs in several stages, including glycolysis, the citric acid cycle, and oxidative phosphorylation.

During this process, glucose is broken down in a series of reactions that release energy. The oxygen taken in is essential for the electron transport chain, which is a critical step in producing ATP efficiently. The end products, carbon dioxide and water, are then expelled from the cell as waste products. This process is vital for providing the energy that cells need to perform various functions, such as growth, repair, and maintenance.

Other options outline different biological processes. The first choice describes photosynthesis rather than cellular respiration, focusing on how plants convert sunlight to energy. The third refers to fatty acid metabolism, which is a type of metabolic process but not a comprehensive description of cellular respiration, which primarily deals with glucose. The fourth option mentions protein synthesis, a distinct process that is not directly related to the production of energy from glucose and oxygen.