13) Photosynthesis Flashcards
4 main structures of the chloroplast
- double membrane
- photosystems I & II
- thylakoid
- fluid stroma
what is the function of the double membrane
- contains grana & stroma
- permeable to CO2, 02, ATP, sugars
what is the function of the photosystems
- provide huge surface area for maximum light absorption
what is the function of the thylakoid related to its structure
- stacked/large sa to increase light absorption
- membrane (w pigments to absorb light) for light-dependent reaction
- space for accumulation of H+ = proton gradient
- green so chlorophyll absorbs red & blue light
what is the function of the fluid stroma
- light-independent reaction/calvin cycle
- has enzymes (RuBP, NADP)
where is the site of Light Dependent Stage (cyclic/non-cyclic phosphorylation)
Thylakoids (grana)
where is the site of Light Independent Stage (calvin cycle)
Stroma
where is the precise location of chlorophyll
Thylakoid membrane
Explain Non-Cyclic Phosphorylation (LDR)
- Accessory pigments in photosystem II absorbs photons of light.
- energy passed onto primary pigment & chlorophyll photoactivated.
- diff wavelengths absorbed.
- photolysis
- O2 production
- energised electrons pass along ETC then to PSI
- ETC sets up proton gradient = chemiosmosis
Explain Cyclic Phosphorylation (LDR)
- only PSI used
- light energy absorbed
- electron excited
- electron emitted from chlorophyll passed along ETC
- protons pumped into thylakoid space
- protons diffuse back to stroma by ATP synthase
- ATP synthesis
- electron returns to PSI
How many photosystems are used in cyclic & non-cyclic phosphorylation
Cyclic = 1
Non-cyclic = both (2)
What are the products in cyclic & non-cyclic phosphorylation
Cyclic = ATP
Non-cyclic = ATP, O2, NADPH
What is the role of NADP reductase
- transfers electrons to NADP
- to form NADP
Chlorophyll A reflects & absorbs what colours ?
absorbs = blue & little violet/orange
reflects = green & little yellow
Chlorophyll B reflects & absorbs what colours ?
absorbs = violet & red
reflects = green & yellow
Cartenoids absorb what colours ?
colours that chlorophyll cannot absorb.
(can be seen in fall when chlorophyll breaks down)
why do plants appear green?
reflection of green light by chlorophyll
Shorter the wavelength, _____ the energy
higher
Longer the wavelength, ____ the energy
lower