Chapter 6 Flashcards
(24 cards)
Chloroplast
Organelle specialized for photosynthesis in plants and some protists.
Wavelength
Distance between the crests of two successive waves.
Photosynthesis
Metabolic pathway by which most autotrophs capture light energy and use it to make sugars from CO2 and water.
Pigment
An organic molecule that can absorb light of certain wavelengths.
Photolysis
Process by which light energy breaks down a molecule.
Electron Transfer Phosphorylation
Process in which electron flow through electron transfer chains sets up a hydrogen ion gradient that drives ATP formation. Also called chemiosmosis.
Light-dependent reactions
First stage of photosynthesis; convert light energy to chemical energy of ATP and NADPH.
Carbon Fixation
Process by which carbon from an inorganic source such as carbon dioxide gets incorporated into an organic molecule.
Light-independent reactions
Second stage of photosynthesis; use ATP and NADPH to assemle sugars from water and CO2.
Rubisco
Ribulose bisphosphate carboxylase. Carbon-fixing enzyme of the Calvin-Benson cycle.
Thylakoid Membrane
A chloroplast’s highly folded inner membrane stystem; forms a continuous compartment in the stroma.
Autotroph
Organism that makes its own food using carbon from inorganic molecules such as CO2, and energy from the environment.
Calvin-Benson Cycle
Light-independent reactions of phtosynthesis; cyclic carbon-fixing pathway that forms sugars from CO2.
Chemoautotroph
Organism that obtains both energy and carbon by breaking down organic compounds.
Heterotroph
Organism that obtains energy and carbon from organic compounds assembled by other organisms.
Photoautotroph
Photosynthetic autotroph.
C3 Plant
Type of plant that uses only the Calvin-Benson cycle to fix carbon.
Stroma
Semifluid matrix between the thylakoid membrane and the two outer membranes of a chloroplast.
CAM Plant
Type of C4 plant that conserves water by fixing carbon twice, at different times of day.
Stomata
Gaps that open on plant surfaces; allow water vapor and gases to diffuse across the epidermis.
Photosystem
Cluster of pigments and proteins that converts light energy to chemical energy in photosynthesis.
Photorespiration
Reaction in which rubisco attaches oxygen instead of carbon dioxide to ribulose bisphosphate.
C4 Plant
Type of plant that minimizes photorespiration by fixing carbon twice, in two cell types.
Chlorophyll a
Main photosynthetic pigment in plants.
