CELS 191 Lecture 7 Flashcards
what process is responsible for almost all the planets energy RESOURCES
photosynthesis
what are chloroplasts and what is their structure
they are the organelles responsible for photosynthesis - they have three lipid bilayers: two around the edge of the cell (inner and outer) as well as one membrane around each thylakoid
why are the thylakoid arranged like discs
to increase surface area
what is the stroma
the substance inside the inner membrane and outside the thylakoid membrane which is similar to the cytosol in the cell
what are the complexes called where chlorophyll is stored and where are they found
photosystems - in the thylakoid membrane
what order are the photosystems in
photosystem 2 then photosystem 1
where do the electrons in the light reactions come from
water being split into oxygen and H+ (protons)
what happens to the electrons in the photosystem complexes
the light energy is absorbed and excites the electrons in chlorophyll and they move to cytochrome complex (from photosystem 2) or an enzyme in the membrane (photosystem 1)
what happens in the cytochrome complex
the electrons lose some of their energy as it is used to pump protons from the stroma into the thylakoid space
what does the enzyme after photosystem 1 do
it combines NADP+, H+ and 2 electrons to make NADPH
what is used to create the proton gradient in photosynthesis
cytochrome complex
what protein complex allows the movement of protons down their concentration gradient
ATP synthase
what are the outputs of the light reactions
O2, NADPH and ATP
where does the Calvin cycle (carbon fixation) take place
the chloroplast stroma
what are the three steps of the Calvin cycle (carbon fixation)
fixation
reduction
regeneration
what are the reactants and products for the fixation (in the Calvin cycle)
the reactants are 3x five carbon molecules and three carbon dioxide molecules these are broken down into 6x three carbon molecules
what are the reactants and products for the reduction (in the Calvin cycle)
the reactants are the 6x three carbon molecules from fixation (which are low energy) and the products are 6x three carbon molecules which are high energy - this process requires 6ATP as well as 6NADPH
what is the output of the Calvin cycle (carbon fixation)
one three carbon molecule which combines with another three carbon molecule to form glucose
in reduction 6x three carbon molecules are formed what happens to these 6 molecules
one of them is released to become glucose and the other five are used in regeneration
what occurs in regeneration (in the Calvin cycle)
6ATP and the 5x three carbon molecules are used to form 3x five carbon molecules that are the same as the ones we started with
