What process do plants use to convert glucose into usable energy?

Plants utilize the process of cellular respiration to convert glucose into usable energy. This process occurs primarily in the mitochondria of plant cells where glucose, derived from photosynthesis, is broken down in the presence of oxygen. During cellular respiration, glucose is oxidized, releasing energy stored in its chemical bonds. This energy is then used to produce adenosine triphosphate (ATP), which serves as the main energy currency for cellular activities in the plant.

While photosynthesis is a crucial process that captures light energy to synthesize glucose from carbon dioxide and water, it does not involve the conversion of glucose into energy. Instead, it sets the stage for cellular respiration by providing the glucose that is later broken down. Transpiration refers to the movement of water through plants and the evaporation of water from their leaves, which is unrelated to energy conversion. Fermentation is a metabolic process that occurs in the absence of oxygen, primarily in some fungi and microorganisms, and is not the preferred method for energy production in most plants. Thus, cellular respiration is the correct answer as it specifically describes the conversion of glucose into usable energy.