Unit 3: Cellular Energetics Flashcards
catabolism
the breakdown of molecules
ex: hydrolysis, cellular respiration, exergonic
anabolism
builds polymers
ex: dehydration synthesis, photosynthesis, endergonic
autotrophs
(producers) use light energy to make organic molecules
heterotrophs
consume organic molecules from other organisms for energy and carbon
photosynthesis
6CO2 + 6H2O + Light Energy -> C6H12O6 + 6O2
converts light energy chemical energy of food
chloroplast
site of photosynthesis in plants found in the cells of the mesophyll (the inner tissue of the leaf)
stroma
dense fluid within chloroplast
stomata
pores in leaf
chlorophyll
green pigment in the thylakoid membranes of chloroplast
redox reaction
water is split, energy transferred with H+ to CO2, sugar water is oxidized, carbon dioxide is reduced
photons
a particle of light absorbed by the chloroplast
light reactions
(thylakoid) split water, release oxygen, produce ATP and NADPH for reducing power
calvin cycle / dark reactions
(stroma) forms sugar from carbon dioxide, using ATP for energy and NADPH for reducing power
photosystem
a reaction center that absorbs different wavelengths of light
calvin cycle: step 1: carbon fixation
Rubisco fixing CO2 to RuBP, producing two molecules of 3-PGA
calvin cycle: step 2: reduction
3-PGA molecules made through carbon fixation are converted into glucose. this stage obtains energy from ATP and NADPH formed during light dependent reactions. G3P exits the cycle
calvin cycle: step 3: regeneration of RuBP
the remaining 5 G3P molecules get rearranged to form 3 RuBP molecules
where do the light reactions take place?
thylakoid membrane
what are the primary cells responsible for photosynthesis
palisade mesophyll
steps of the light dependent reactions: photolysis
step 1: light strikes chlorophyll in photosystem II, causes electrons to become excited
step 2: water is split to replace electrons lost by photosynthesis II, this produces hydrogen ions
as electrons travel down the electron transport chain (ETC) their energy is used to pump hydrogen ions across the membrane into the …
thylakoid space
what does light do when it strikes the chlorophyll molecules of photosystems I and II?
light causes electrons to get excited (gain energy) and travel down an electron transport chain embedded in the thylakoid membrane
after light excites electrons and they leave photosystem II to travel down the first electron transport chain, how are these electrons replaced to photosystem II?
water is split and the electrons are given to the chlorophyll molecules of photosystem II
exergonic
metabolic process involving release of energy
endergonic
metabolic process involving absorbing energy
