Introduction to Photosynthesis and Plant Energy Metabolism

Vocabulary flashcards covering the key terms, structures, and processes of photosynthesis, chloroplast anatomy, light absorption, and plant energy metabolism.

Photosynthesis

The biological process of capturing light photons and transferring them into chemical energy.

Photoautotrophs

Organisms such as trees, grasses, ocean plankton, and seaweed that carry out photosynthesis to produce energy and oxygen.

Autotrophs

Organisms that obtain their carbon directly from inorganic carbon dioxide and convert it into organic carbon compounds.

Chemotrophs

Organisms, such as extremophiles near methane vents in the Marianas Trench, that chemically convert earth-based sources into energy rather than relying on sunlight.

Xylem

Vessels in leaves and plant trunks that allow water to pass and be pulled upward to maintain cell shape, structure, and life.

Stomata

Vessel-like structures on the underside of a leaf that open and close to regulate gas exchange, taking in carbon dioxide and releasing oxygen.

Thylakoids

Flat, oblong, frisbee-shaped reaction centers inside chloroplasts where light is harvested and light-dependent reactions occur.

Granum

A stack of thylakoid discs located within the chloroplast.

Visible Light

The specific range of wavelengths within the electromagnetic spectrum that human eyes can detect and that powers photosynthesis.

Chlorophyll Alpha

The primary photosynthetic pigment in green plants that absorbs specific wavelengths of light at two distinct peaks while reflecting green light.

Carotenoids

Accessory pigments that absorb different light waveforms than chlorophyll alpha, reflecting colors like blues, purples, and yellows to maximize light capture.

Senescence

The seasonal aging and dying process of leaves, during which a tree reclaims nutrients for winter storage, revealing accessory carotenoid pigments before the leaves turn brown and drop.

Photosystems

Protein complexes located on the thylakoid membrane that contain chlorophyll molecules and serve as the sites where photons excite electrons.

Chlorophyll Oxidation

The process occurring when an excited chlorophyll molecule loses an electron to an electron acceptor, officially launching the photosynthetic electron transport process.

Calvin Cycle

The light-independent reactions occurring in the chloroplast that utilize ATP to assemble long-term stored energy in the form of sugar rings and chains.

Nitrogen-Fixing Bacteria

Microorganisms present in plant root systems that convert environmental nitrogen or ammonia into a form that plant cells can take up and utilize.