Looks like no one added any tags here yet for you.
autotroph
“self feeders”, takes co2 → organic molecules and can sustain life w/o eating other organisms
heterotroph
“different feeders”, other organisms → organic molecules, depends on photoautotrophs for food and o2; they cannot exist without autotrophs
photoautotroph
uses energy from sun, takes h2o and co2 → organic molecules, includes plants, algae, some protists and prokaryotes
stroma
dense fluid inside chloroplasts that is outside of the thylakoids; similar to cytoplasm but for chloroplasts
thylakoid
connected sacs in the chloroplast, contains chlorophyll
granum
stacks of thylakoids are called
lumen
location of the ETC in photosynthesis
photosynthesis equation
6co2 + 6h2o + light energy (photons) → c6h12o6 + 6o2
mesophyll
interior tissue of the leaf containing 30-40 chloroplasts
stomata
pores on leaves that allows co2 to enter and o2 to exit
photo vs cell
photosynthesis
endergonic
reduces co2 → sugar
cellular respiration
exergonic
oxidizes sugar → co2
light rxn and calvin cycle
these are the two steps of photosynthesis, where h2o splits into h2 and o2 with the electrons being taken from them
light rxns
in the thylakoid membrane, this is step one of the photosynthesis process:
split h2o
reduce NADP+ to NADPH
generate ATP from ADP via photophosphorylation
release o2
calvin cycle
in the stroma, this is step two of the photosynthesis process
ATP and NADPH → CO2 → G3P
IN ORDER: carbon fixation, reeduction, regeneration of CO2 acceptor
chlorophyll
within thylakoid membranes, these reflect and transmit green light and are pigments within chloroplasts; photon absorbed by ________ → reflects green
visible light
wavelengths that produce colors we can see, being 380nm to 750nm
photons
also known as sunlight
chlorophyll a
the main photosynthetic pigment that contain colors violet, blue, and red
accessory pigments
alongside chlorophyll a, these are in place to broaden the spectrum of colors and absorb excessive light that would otherwise damage chlorophyll; chlorophyll b and carotenoids
carotenoids
these are a type of accessory pigment that transmits yellow, orange, or red light and is responsible for leaf color in fall
absorbs light
when a pigment _________, electrons move from a ground state to an excited state, giving off heat or fluorescence, allowing acceptance through an electron acceptor in a redox reaction, exciting nearby pigments, or dropping back down in energy levels
photosystem
consists of a reaction-center complex surrounded by light-harvesting complexes (aka pigment molecules) which funnel the energy from photons → reaction center
pheophytin
a primary electron acceptor in PSII, accepts an excited electron; being a pigment molecule structurally similar to chlorophyll
photosystem 2
in the thylakoid membrane, this is one of the photosystems that usually functions first, is best at absorbing wavelength 680nm and reaction-center chlorophyll a is p680
photon hits pigment
light energy passes amongst pigment molecules → excites p680
excited electron from p680 → primary electron acceptor pheophytin
H2O split by enzymes, electrons transferred from the H atoms to P680+, reduced to P680
O2 byproduct
photosystem 1
in the thylakoid membrane, this is one of the photosystems that is best at absorbing wavelength 700nm and reaction center a is p700
photon hits pigment
P700 accepts replacement electrons from PSII via ETC
electron passes → primary electron acceptor ferredoxin
pmf
energy released by the fall of electrons down the etc creates this across the thylakoid membrane, with the diffusion of H+ (protons) back across the membrane driving ATP synthesis
ferredoxin
primary electron acceptor of PSI
cytochrome complex
this structure provides a connection between PSII and PSI, allowing plastoquinone produced by both products to pass through to generate ATP
NADPH
product of PSI, made by enzyme NADP+ → transfer proton and two electrons from ferredoxin → forms ____________
ATP
product of PSII, made by the pmf
linear electron flow
the primary pathway involving both photosystems and produces ATP and NADPH using light energy
cyclic electron flow
using only PSI and produces ATP, but not NADPH; good for generating surplus ATP to satisfy the higher demands in the calvin cycle
mitochondria vs chloroplast
intermembrane space → thylakoid lumen
inner membrane → thylakoid membrane
matrix → stroma
ETC: inner membrane → thlakoid membrane
PMF: intermediate space → thylakoid lumen
ATP synthase: inner membrane → thylakoid membrane
ATP location: mitochondrial matrix → stroma
rubisco
important CO2-fixing enzyme in the calvin cycle. most abundant enzyme on earth yet most demanding
inefficent, catalyzes addition of CO2 to RUBP and addition of O2 to RUBP
adds CO2 + RUBP → G3P
one molecule is released for every five that continue around the cycle
photorespiration
rubisco adds O2 instead of CO2 in the calvin cycle
O2 and organism fuel → release CO2, using extra ATP and producing no ATP or G3P
carbon fixation favored over this process when CO2 high O2 low
hot dry conditions are favored for this process
RUBP
in the calvin cycle, this is used to generate a 6 carbon molecule of G3P and is regenerated once five G3Ps are available, then recycled to regenerate the acceptor, requiring ATP in the process
c4 plants
plants that minimize the cost of photorespiration by incorporating CO2 into four-carbon compounds by using enzyme PEP carboxylase
PEP carboxylase
this enzyme has a higher affinity for CO2 than rubisco and can fix CO2 even when CO2 concentrations are low
cam plants
plants able to open their stomata at night → take in CO2 → close during day → CO2 released from organic acids → use in calvin cycle
sun
even though PSII works before PSI does, the ____ is hitting them both at the same time and they work at the same time