photosynthesis part2 Flashcards
how do photosynthetic pigments absorb specific wavelenths of light energy
-e- in chlorophyll absorb a photon of light
-photoon of the right energy level (wavelength) excites e- to a higher energy orbital
-e- emits energy as it returns to lower energy state
what can neighboring pigemnt molecules do with each other
can pass energy from one pigment to another (CHECK IMAGE ON NOTES)
what do most pigment moleqs compose
the photosystems antenna complex or light harvesting complex
what are pigments organized into
complexes called photosystems that optimize the transfer of energy
pigment molecules and proteins make up
a photosystem
a pair of specialized chlorophyll a moleq are the only what
only chlorophyll moleqs that can give up their e- to another moleq
what does the primary e- acceptor protein receive
e- from those specialized chlorphyll moleq
what is a rxn center
a protein pigment complex that includes 2 specialized chlorophyll a moleqs that can donate e- to to the receiving protein
what does the primary e- acceptor in rxn accepts
e- and its reduced as a result
first protein in an
etc
what does the primary e- acceptor donate
the e- to the next protein in the ETC
check two images for texts representation of photosystem vs ribbon model
ok
the two photosystmems (I and II) are embedded where
in thylakoid membranes that function in photosynthesis
the two photosystems differ hiw
in theur reaction center chlorophylls
what links the two photosystems together
one ETC links the two together
what does the second ETC do with photosystem I
another delivers e- to NADP+ to make NADPH
what are associated with two photosystems
two short ETC
light energy drives….? what is is absorbed by?
drives the syntehsis of NADPH and ATP and aborbsed by the pugments in the antenna complex
what resupplies the e- needed for PS II for the synthesis of NADPH
H2O
H2O -> O2 + e- + H+
electron flow from PS II to I also leads to what
synthesis of ATP by chemiososomos
stroma pH =
8
thylakoid lumen pH =
5
e- flow in photosystems is just like what?
like it is in mitochondria. e- flow (exergonic process) provides energy to pump H+ across a membrane (endergonic process) against [] gradient
proton flow in photosynthesis is juts like
in mitochondria: proton flow through ATP synthase compelx (exergonic) provides the energy to synthesize ATP from ADP and Pi (endergonic)
light rxns generate what
ATP and inc the potential energy of e- by moving them from H2O to NADPH
where are ATP and NADPH produced
on the side facing the stroma where the calvin cycle takes place
ATP is made by ___________
-using what?
-focus is on what?
photophosphorylation
-using light energy to synthesize ATP form ADP and Pi
-focus on ultimate source of energy for making ATP
what is ATP also made by besides photophosphorylation?
-using
-where else
chemiosmosis
-uses protons motive force of diffusing H+ to provide the energy for synthesizing ATP from ADP and Pi
-also made by chemiosmosis in mitochondria during aerobic respiration
ATP is made by photophosphorylation and chemisosis. Which is true?
both are true. one term focuses on the original source of energy while the other focuses on the mechanisms by whic the ATP is made
