Photosynthesis Vocabulary

autotroph
An organism that obtains organic food molecules without eating other organisms or substances derived from other organisms. Autotrophs use energy from the sun or from the oxidation of inorganic substances to make organic molecules from inorganic ones.
Calvin cycle
The second of two major stages in photosynthesis (following the light reactions), involving atmospheric CO2 fixation and reduction of the fixed carbon into carbohydrate.
chloroplast
An organelle found only in plants and photosynthetic protists that absorbs sunlight and uses it to drive the synthesis of organic compounds from carbon dioxide and water.
granum
(plural, grana) A stacked portion of the thylakoid membrane in the chloroplast. Grana function in the light reactions of photosynthesis.
greenhouse effect
The warming of planet Earth due to the atmospheric accumulation of carbon dioxide, which absorbs infrared radiation and slows its escape from the irradiated Earth.
light reactions
The steps in photosynthesis that occur on the thylakoid membranes of the chloroplast and that convert solar energy to the chemical energy of ATP and NADPH, evolving oxygen in the process.
photon
A quantum, or discrete amount, of light energy.
photosystem
The light-harvesting unit in photosynthesis, located on the thylakoid membrane of the chloroplast. There are two types of photosystems, I and II; they absorb light best at different wavelengths.
producers
Organisms that make organic food molecules from CO2, H2O, and other inorganic raw materials: a plant, alga, or autotrophic bacterium.
stomata
A microscopic pore surrounded by guard cells in the epidermis of leaves and stems that allows gas exchange.
stroma
The fluid of the chloroplast surrounding the thylakoid membrane; involved in the synthesis of organic molecules from carbon dioxide and water.
thylakoid
A flattened membrane sac inside the chloroplast, used to convert light energy to chemical energy.
wavelength
The distance between crests of waves, such as those of the electromagnetic spectrum.