17.3 photosynthesis
3/09/23
Chloroplast structure
- Photosynthesis = of glucose molecules from light energy →
combined to make starch ( energy storage)
- Chloroplast = double membrane ( inner + outer membrane)
Structures:
- Dna = codes for enzymes needed in photosynthesis reaction
- Ribosomes = make enzymes
- Starch = energy storage
- Thylakoid stacked → granum
- Grana connected by intergranal lamella
Light dependent stage ( z scheme)
- Thylakoid = light dependent stage ( z - scheme)
- Within thylakoid membrane there is photosystems 1 and 2 in the membrane
- These photosystems are made out of photosynthetic pigments which
absorb the light
pigments :
Primary pigment
- = chlorophyll a( absorbs red and blue + reflects green)
Accessory pigments
- = help absorb light energy when chlorophyll a is not functioning properly
(absorb different wavelengths to chlorophyll a - different combos of
pigments is reason for diff shades and colours on leaves)
- Carotenoids = yellow orange colours seen
- Anthocyanins = produce red /purple
- carotenoids , xanthophylls and chlorophyll b → these are all
embedded in thylakoid membrane of chloroplast → forms light
harvestign system aka antennae complex → system role is to absorb
light energy of different wavelengths + transfer energy quickly to
chlorophyl a in reaction centre → so photosynthesis takes place
- The light harvesting system + reaction centre = photosystem
After reactions occur in LD stage → substrate move to stroma → this is where
light independent stage occurs (aka calvin cycle)
3/09/23
Chloroplast structure
- Photosynthesis = of glucose molecules from light energy →
combined to make starch ( energy storage)
- Chloroplast = double membrane ( inner + outer membrane)
Structures:
- Dna = codes for enzymes needed in photosynthesis reaction
- Ribosomes = make enzymes
- Starch = energy storage
- Thylakoid stacked → granum
- Grana connected by intergranal lamella
Light dependent stage ( z scheme)
- Thylakoid = light dependent stage ( z - scheme)
- Within thylakoid membrane there is photosystems 1 and 2 in the membrane
- These photosystems are made out of photosynthetic pigments which
absorb the light
pigments :
Primary pigment
- = chlorophyll a( absorbs red and blue + reflects green)
Accessory pigments
- = help absorb light energy when chlorophyll a is not functioning properly
(absorb different wavelengths to chlorophyll a - different combos of
pigments is reason for diff shades and colours on leaves)
- Carotenoids = yellow orange colours seen
- Anthocyanins = produce red /purple
- carotenoids , xanthophylls and chlorophyll b → these are all
embedded in thylakoid membrane of chloroplast → forms light
harvestign system aka antennae complex → system role is to absorb
light energy of different wavelengths + transfer energy quickly to
chlorophyl a in reaction centre → so photosynthesis takes place
- The light harvesting system + reaction centre = photosystem
After reactions occur in LD stage → substrate move to stroma → this is where
light independent stage occurs (aka calvin cycle)
