Chapter 5: Photosynthesis Flashcards
photosynthesis
an autotrophic process that uses light energy and simple molecules to make carbohydrates
carbon fixation
the incorporation of carbon (in the form of carbon dioxide) into organic molecules such as carbohydrates
photolysis
the first part of photosynthesis in which light energy splits water molecules
granum
a stack of thylakoids, which function in the light reaction of photosynthesis
thylakoid
a flat sac in the chloroplast, which converts light energy to chemical energy
light-harvesting antennae
groups of pigments that help capture energy from light in a photosystem and pass the light to the reaction center
stroma
the fluid surrounding the grana inside the chloroplast
pigment
a substance that is able to absorb light
action spectrum
shows the effectiveness of different wavelengths of light on photosynthesis
absorption spectrum
plots the absorbance against the wavelength of light for a specific pigment
carotenoids
a chemical that aids in light absorption for photosynthesis where chlorophyll a and b cannot pick up light
photoelectric effect/photoexcitation
light’s ability to elevate electrons to a more excited state
discrete quanta
unconnected distinct amounts (i.e. photon: a particle of light)
ground state
the natural energy state of an electron
reaction center
the location of the chlorophyll a molecule that will lose an excited electron in a photosystem
photosystem
a light-harvesting group of pigments
NADPH reductase
the enzyme that reduces NADP to NADPH + H
a primary electron acceptor
chlorophyll a’s electron can only be passed to . . .
ferredoxin
a membrane protein that gains an electron during photosystem I
cyclic electron flow
occurs when there is a buildup up NADPH, resulting in electrons being passed down a transport chain and eventually forming ATP
photophosphorylation
the production of ATP from cyclic electron flow
rubisco
an enzyme that catalyzes the first step in the Calvin cycle
C3 plants
plants that obtain a 3-carbon molecule as the result of carbon fixation
C4 plants
plants that obtain a 4-carbon molecule as the result of carbon fixation
bundle sheath cell
a distinct type of cell found in C4 plants that is arranged around the veins of the leaf. The Calvin cycle occurs in the chloroplast of these cells.
CAM plants
plants that produce organic acids from CO2 at night, and release CO2 in the day
halophile
an organism that can grow in saline conditions
bacteriorhodopsin
a light-absorbing chemical found in bacteria that functioned as an antenna in Archaea which aided in the production of ATP
