- Autotrophs
- Heterotrophs
- Green parts do photosynthesis
- Mesophyll tissues in leaf contain the cells that do photosynthesis
- Chloroplasts are organelles reponsible for photosynthesis
- Stoma
- Cuticle
- Choloroplasts
- Thylakoid membranes
- flattened into disks called grana(singular)/granum(stack/plural)
- Stroma
- semi-fluid substance(matrix) inside Chloroplasts
- Calvid Cycle occurs here
- Thylakoid membranes
-
6 CO2 + 6 H20 ----> C6H12O6 + 6O2
-
Oxyidation-Reduction Reaction(redox)
- a reaction that involves the movement of electrons from one molecule to another
- Reduction: gain of electrons (gain a H+)
- Oxidation: loss of electrons (lose a H+)
-
NADP+ ----> NADPH (electron shuttle molecule)
-
Only occur when solar energy is available
-
Takes place in thylakoid membranes of chloroplasts.
-
Photosystem I and Photosystem II (Order of discovery not occurence)
-
Calvin Cycle Reactions (not dependent on light)
- an enzymatic reaction in which carbon dioxide is reduced to a carbohydrate in the stroma of chloroplasts
- (ATP/NADPH) ---> Carbohydrates
- Consists of two photosystems: PS I and PS II
- Photosystem II
- Step 1: water is split, electron released
- Step 2: Electrons take up by pigment complex (chlorophyll carotenoids)
- electrons get some energy
- Step 3: Electrons are sent to reaction center (two special chlorphyll a molecules)
- they are supercharged
- Step 4: Electron fly off reaction center and caught by electron acceptor molecule
- Step 5: High energy electrons are sent on Electron Transport Chain
- ATP is created by this, which is sent to stroma(Calvin Cycle)
- Photosystem I
- Step 1: receives low energy electrons from the ETC of PS II
- Step 2: electrons are sent to pigment complex
- Step 3: get sent to reaction center, superchaged
- Step 4: high energy electrons are picked up by NADP+, which makes NADPH and sent to stroma(Calvin Cycle)
-
Takes place in stroma
-
Step 1(fixation of CO2): CO2 is joined to RuBP to make 6-carbon intermediate
-
Step 2(reduction of CO2): the 6-carbon molecule is converted to many 3-carbon molecules (3GP), uses ATP and NADPH
- Product: G3P
-
Step 3(regeneration of RuBP): ATP is used to create RuBP
-
G3P is the base for all the carbohydrates
- C3 in hot weather have to close stomata to conserve water
- O2 levels increase in leaf tissues
- problem: if o2 levels are higher than co2, then the enzyme RuBP carboxylase will bind to O2 instead (bad)
- photorespiration, i.e. bad
- ex: maples, azaleas, wheat
- C4 and CAM
- avoid photorespiration
- use enzyme PEPcase instead of RuBP carboxylase
- separate reactions by location
- light reactions in mesophyll
- calvin cycle in bundle sheath cells
- c4 ex: sugar cane, corn, bermuda grass
- cam ex: cacti, pineapple, succulents