5.6.1 interrelationship between photosynthesis & respiration Flashcards
define photosynthesis
light energy from sun transformed into chemical energy & can be used to synthesise large organic molecules from smaller inorganic molecules
define autotroph
organisms that use energy to synthesise large organic molecules from smaller inorganic molecules
define heterotroph
organisms that rely on other plants/animals to obtain energy
define photoautotroph
organisms which use light energy to synthesise large organic molecules from smaller inorganic ones
what are organisms which photosynthesise known as
- photoautotroph
- producers
equation for photosynthesis
6CO2 + 6H20 + energy from protons —-(chlorophyll)—> C6H12O6 + 6O2
what is photosynthesis an example of
carbon fixation (carbon dioxide converted into sugars)
describe carbon fixation
- endothermic = requires energy
- needs electrons
equation for respiration
C6H12O6 + 602 —–> 6H2O + 6CO2 + energy
describe the interrelation between photosynthesis & respiration
- both important for cycling carbon dioxide & oxygen
- products of one process are raw materials for other process (aerobic respiration removes oxygen & adds carbon dioxide, photosynthesis does the opposite)
how often do plants respire/photosynthesise
respire = 24/7
photosynthesise = daylight
why must the light intensity be sufficient
to allow photosynthesis at a rate which will replenishes carbohydrates stores used up by respiration
define the compensation point
when photosynthesis & respiration proceed at the same rate, so no net gain or loss of carbohydrate
define compensation period
the time a plant takes to reach the compensation point 9 (different for different species)
compensation point for shade-loving plants
can utilise lower intensity of sunlight & reach compensation point sooner
