Term | Definition |
ATP | adenosine triphosphate, an organic molecule that acts as the main energy source for cell processes; composed of a nitrogenous base, a sugar, and three phosphate groups |
ADP | low-energy molecule that can be converted to ATP |
chemosynthesis | process by which ATP is synthesized by using chemicals as an energy source instead of light |
photosynthesis | process by which plants, algae, and some bacteria use sunlight, carbon dioxide, and water to produce carbohydrates and oxygen |
chlorophyll | a green pigment that is present in most plant and algae cells and come bacteria that gives plants their characteristic green color, and that absorbs light to provide energy for photosynthesis |
thylakoid | a membrane system found within chloroplasts that contains the components for photosynthesis |
light-dependent reaction | part of photosynthesis that absorbs energy from sunlight and transfers energy to the light-independent reactions |
light-independent reaction | part of photosynthesis that uses energy absorbed during the light-dependent reactions to synthesize carbohydrates |
photosystem | series of light-absorbing pigments and proteins that capture and transfer energy in the thylakoid membrane |
electron transport chain | a series of molecules, found in the inner membranes of mitochondria and chloroplasts, through which electrons pass in a process that causes protons to build up on one side of the membrane |
ATP synthase | enzyme that catalyzes the reaction that adds a high-energy phosphate group to ADP to form ATP |
Calvin cycle | a biochemical pathway of photosynthesis in which carbon dioxide is converted into glucose using ATP |
cellular respiration | the process by which cells produce energy from carbohydrates; atmospheric oxygen combines with glucose to form water and carbon dioxide |
aerobic | process that requires oxygen to occur |
glycolysis | the anaerobic breakdown of glucose into pyruvic acid, which makes a small amount of energy available to cells in the form of ATP |
anaerobic | describes a process that does not require oxygen |
Krebs cycle | a series of biochemical reactions that converts pyruvic acid into carbon dioxide and water; it is the major pathway of oxidation in animal, bacterial,and plant cells, and it releases energy |
fermentation | breakdown of carbohydrates by enzymes, bacteria, yeasts, or mold in the absence of oxygen |
lactic acid | product of fermentation in many types of cells, including human muscle cells |