5.3 PMT Flashcards
describe 2 ways in which the grana is adapted to its function
-the membranes containing the pigments have a large surface area for absorbing light
-there is a large surface area for the electron transport chain.
why is temp a limiting factor
its important for the light independent reaction which involves enzymes
outline the ways in which heterotrophic organisms are dependent on plants
-animals need to obtain organic material from plants
-plants produce organic material during photosynthesis ( calvin cycle)
-plants produce oxygen during photosynthesis (photolysis)
-glucose/ carbohydrate/oxygen (produced in photosynthesis) is used in respiration by animals
whats an autotroph
can make organic molecules from inorganic molecules
whats a heterotroph
relies on organic molecules that have been made by another organism
how is light harvested from chloroplast membranes (5)
-primary and accessory pigments are in photosystems
-photon (light energy) absorbed by pigment molecule
-electron becomes excited and moves to a higher energy level
-energy/ photon is passed from one pigment to another and to chlorophyll A
- a range of accessory pigments allow for a range of wavelengths to be absorbed
what happens when the movement of electrons are blocked from moving between electron carriers
-prevents non-cyclic photophosphorylation
-no electrons available to form reduced NADP
-less ATP and no reduced NADP available for Calvin cycle
discuss why measuring co2 uptake may or may not give a better indication of photosynthetic activity than measuring O2 production
-some oxygen is used in respiration
-oxygen is only produced in one stage of photosynthesis so cant measure other areas of activity
-CO2 only measures the rate of the calvin cycle
-some used in photosynthesis
how can binding to electrons in photosystem one cause death of a plant
-prevents photophosphorylation (cyclic and non cyclic)
-no ATP and reduced NADP for calvin cycle.
-no substrate made from respiration
