Chapter 5 Flashcards
An organism that converts energy from sunlight or from inorganic chemical compounds in the environment into chemical energy stored in the carbon–carbon bonds of organic compounds.
Autotroph
A biochemical pathway involving the uptake of CO2 by the enzyme ribulose 1,5 bisphosphate carboxylase/oxygenase (rubisco) and synthesis of sugars by the Calvin cycle.
C3 photosynthetic pathway
A biochemical pathway involving the daytime uptake of CO2 by the enzyme phosphoenol pyruvate carboxylase (PEPcase) in mesophyll cells; the carbon is then transferred as a four-carbon acid to the bundle sheath cells, where CO2 is released to the Calvin cycle for sugar synthesis.
C4 photosynthetic pathway
The biochemical pathway used by photosynthetic and chemosynthetic organisms to fix carbon and synthesize sugars.
Calvin Cycle
The use of energy from inorganic chemical compounds to fix CO2 and produce carbohydrates using the Calvin cycle; also called chemolithotrophy.
chemosynthesis
A photosynthetic pathway in which CO2 is fixed and stored as an organic acid at night, then released to the Calvin cycle during the day.
crassulacean acid metabolism (CAM)
Freshly dead or partially decomposed remains of organisms.
Detritus
(1) The uptake of the gaseous form of a compound, including CO2 in photosynthesis and N2 in nitrogen fixation, by organisms for use in metabolic functions. (2) With respect to the genetic composition of a population, an allele frequency of 100%.
Fixation
An organism that obtains energy by consuming energy-rich organic compounds made by other organisms.
Heterotroph
A chemical reaction in photosynthetic organisms in which the enzyme rubisco takes up O2, leading to the breakdown of sugars, the release of CO2, and a net loss of energy.
Photorespiration
A process that uses sunlight to provide the energy needed to take up CO2 and synthesize sugars.
Photosynthesis
