c1.2 - photosynthesis Flashcards
chloroplast
organelle found in plants + green algae
site of photosynthesis
structure of chloroplast
double membrane
grana - stacks of flattened disks (thylakoid) contains ps1 + ps2, ETC, atp synthase
grana connected by intergranal lamellae
stroma
- fluid filled matrix contains enzymes
where are chloroplasts located in angiosperm leaf
mainly in palisade layer
chloroplast adaptations for photosynethis
- thylakoids give large SA for light independent reactions
- photosynthetic pigments affra ged in photosys5ems to maximise light absorption
- stroma directly surrounds grana = products of photosynthesis diffuse directly into stroma
- contain DNA + ribosomes
inner membrane less permeable than outer, enabling control over movement of substances
angiosperm leaf adaptations for photosynthesis
- large SA to maximise light absorption
- think to reduce diffusion distance for co2
- upper epidermis transparent allowing light to strike mesophyll layers
- palisade cells densely packed + contain many chloroplasts
- air spaces reduce diffusion distance for co2
- vein network transports water + minerals to lead to+ takes sugars away
- stomata allow co2 to diffuse into leaf
transducer, why are chloroplasts described as transducers
- something converts one type of energy into another
- transduce light energy into chem energy of ATP
photosynthetic pigment
molecule present in chloroplasts that absorb light energy for photosynthesis
absorbs specific light wavelengths c reflects ithers
examples of photosynthetic pigments
- chlorophyll a+b
- carotenoids
- xanthophylls
why range of photosynthetic pigments
absorbs range of light wavelengths
purpose of chromatography
separates different products from a mixture of
equation used to calculate Rf
distance travelled by component
Rf = ————————————————
distance traveled by solvent
photosynthesis
complex metabolic pathway that synthesises organic molecules from co2 + water in presence of light
6CO2 + 6H2O -> C6H12O6 + 6O2
stages of photosynthesis
light dependent
light independent
photosystem
- protein complex consisting of antennae complex + reaction centre
- involved in absorption of light + transfer of electrons in photosynthesis
- two types: ps1 + ps2
difference between ps1 + ps2
absorb different light wavelengths
process of light harvesting
- antennae complex absorbs light energy of varying wavelengths + transfers it quickly and efficiently to reaction centre
- energy absorbed by two chlorophyll a molecules which emit excited electrons
absorption spectrum
pattern of bands that occurs when a substance absorbs different wavelengths of light