photosynthesis
the process by which plants, algae, and some bacteria use sunlight, carbon dioxide, and water to produce carbohydrates and oxygen
autotroph
an organism that produces its own nutrients from inorganic substances or from inorganic substances or from the environment instead of consuming other organisms
heterotroph
an organism that obtains organic food molecules by eating other organisms or their by-products and that cannot synthesize organic compounds from inorganic materials
cellular respiration
the process by which cells produce energy from carbohydrates; atmospheric oxygen combines with glucose to form water and carbon dioxide
pigment
a substance that gives another substance or a mixture its color
chlorophyll
a green pigment that is present in most plant cells, that gives plants their characteristic green color, and that reacts with sunlight, carbon dioxide, and water to form carbon dioxide
carotenoid
a class of pigments that are present mostly in plants and tat aid in photosynthesis
thylakoid
a membrane system found within chloroplasts that contains the components for photosynthesis
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
NADPH
an electron carrier that provides the high-energy electrons needed to make carbon-hydrogen bonds in the third stage of photosynthesis
carbon dioxide fixation
the transfer of carbon dioxide to organic compounds
Calvin cycle
a biochemical pathway of photosynthesis in which carbon dioxide is converted into glucose using ATP
aerobic
describes a process that requires oxygen
anaerobic
describes a process that does not require oxygen
glycolysis
the anaerobic breakdown of glucose pyruvic acid, which makes a small amount of energy available to cells in the form of ATP
NADH
an electron carrier that forms from NAD+ as glucose is broken down
Krebs cycle
a series of biochemical reactions that convert pyruvic acid into carbon dioxide and water; it is the major pathway of oxidation in animal, bacterial, and plant cells, and it releases energy
FADH2
an electron carrier that is formed by FAD when electrons are transferred
fermentation
the breakdown of carbohydrates by enzymes, bacteria, yeasts, or mold in the absence of oxygen