Topic 6: Energy and Nutrient Relationships Flashcards
Autotroph
an organism that can synthesize organic molecules using inoragnic molecules and energy from either sunlight or from inorganic molecules, such as hydrogen, sulphide
C3 photosynthesis
the photosynthetic pathway used by most plants and all algae, in which the product of the initial reaction is phosphoglyceric acid, or PGA, a 3 carbon acid
C4 photosynthesis
photosynthesis in which CO2 is fixed in mesophyll cells by combining it with phosphoenolpyruvate, or PEP, to produce a 4 carbon acid. Plants using C4 photosynthesis are generally more drought tolerant than plants employing C3 photosynthesis
CAM photosynthesis
a photosynthetic pathway largely limited to succulent plants in arid and semiarid environments, in which carbon fixation takes place at night, when lower temperatures reduce the rate of water loss during CO2 uptake. the resulting 4 carbon acids are stored until daylight, when they are broken down into pyruvate and CO2.
Carnivore
organisms that consume flesh - approximately synonymous with predator.
chemosynthetic autotroph
autotrophs that use inorganic molecules as a source of carbon and energy
detritivore
organisms that feed on non living organic matter
functional response
an increase in animal feeding rate, which eventually levels off, that occurs in response to an increase in food availability
handling time
the amount of time it takes the predator to handle the food, beginning from the time the predator finds the prey item to the time the prey item is eaten.
herbivore
organism that eats plants
heterotroph
an organism that uses organic molecules both as a source of carbon and a source of energy
light compensation point
the amount of light necessary for a plants respiration rate to equal its photosynthetic rate
light saturation point
is the intensity at which additional increases in light do not increase photo-synthesis
marginal value theorem
developed by Eric Charnov, a theory based on optimality, which describes the “optimal” time for a forager to move from one food patch to another
mixotroph
the ability to gain energy both from photosynthesis and from consuming organic or inorganic compounds
omnivore
hetertorophic organisms that eat a wide range of food items, usually including both animals and plant matter
optimal foraging theory
attempts to model how organisms feed as an optimizing process, a process that maximizes or minimizes some quantity, such as energy intake or predation risk
PA (photosynthetically active radiation)
wavelengths of light between 400 - 700 nm that photosynthetic organisms use as a source of energy
photosynthetic autotroph
describes organisms capable of photosynthesis
P max
the maximum rate of photosynthesis
prey switching
is the frequency dependent predation, where the predator preferentially consumes the most common type of prey
primary producer
autotrophs or primary producers are organisms that acquire their energy from sunlight and materials from nonliving sources
primary predator
predators such as birds and foxes join the food chain by eating the plant eaters and are known as primary consumers. These predators may become food for the next animal up the chain
search cost
the time, energy, and money that buyers and sellers in a market expend in tying to find one another in order to engage in transactions
secondary predator
occurs when one predator feeds on a second predator, which has in turn eaten a target prey.
