B4: photosynthesis

heterotrophs

obtain E by consuming food

autotrophs

make their own food via photosynthesis

photosynthesis equation

6 CO2 + 6 H2O —> C6H12O6 + 6 O2

carbon fixation

incorporating an inorganic carbon (CO2) into an organic molecule (like glucose)

cellular respiration equation

C6H12O6 + 6 O2 —> 6 CO2 +6 H20

epidermis

provides protection & prevents water loss

palisade mesophyll

many chloroplasts, major site of photosynthesis due

spongy mesophyll

loose arrangement for gas exchange

stromata

pores for gas exchange

guard cells

regulate opening/closing of stromata

outer & inner membrane

each made of phospholipid bilayers

stoma

fluid w in chloroplast, site of Calvin cycle

thylakoid

membranes within the storma, site of light dependent rxns

granum

a “stack” of thylakoids

lumen

inside of the thylakoid, accumulates proton ions (inc acidity)

rxn center

chlorophyll pair in the center converts light E to chemical E

photolysis

light E used to split water; electrons passed to PSII protons remain in lumen

carbon fixation

RuBisCo combines CO2 & 5-carbon RuBP, forming a 6-carbon compound that quickly splits into two 3-carbon PGA molecules

reduction

PGA phosphorylated by ATP & reduced by NADPH to form G3P

regeneration

most G3P is converted back to RuBP

carbohydrate synthesis

some G3P is used to make glucose `