Ch. 10 Vocab Flashcards
a graph that profiles the relative effectiveness of different wavelengths of radiation in driving a particular process
action spectrum
an organism that obtains organic food molecules without eating other organisms or substances derived from other organisms; use energy from the sun or from the oxidation of inorganic substances to make organic molecules from inorganic molecules
autotrophs
In C4 plants, a type of photosynthetic cell arranged into tightly packed sheaths around the veins of a leaf
bundle-sheath cells
a plant that used the Calvin cycle for the initial steps that incorporate CO2 into organic material, forming a three-carbon compound as the first stable intermediate
C3 plant
a plant in which the Calvin cycle is preceded by reactions that incorporate CO2 into a four-carbon compound, the end product of which supplies CO2 for the Calvin cycle
C4 plant
a green pigment located within the chloroplasts of plants and algae in the membranes of certain prokaryotes
chlorophyll
a photosynthetic pigment that participates directly in the light reactions, which convert solar energy to chemical energy
chlorophyll a
an accessory photosynthetic pigment that transfers energy to chlorophyll a
chlorophyll b
a route of electron flow during the light reactions of photosynthesis that involves only photosystem I and that produces ATP but not NADPH or O2
cyclic electron flow
the second of two major stages in photosynthesis involving fixation of atmospheric CO2 and reduction of the fixed carbon into carbohydrate
Calvin cycle
accessory pigments, either yellow or orange, in the chloroplasts of plants and in some prokaryotes; broaden the spectrum of colors that can drive photosynthesis by absorbing wavelengths of light that chlorophyll can’t
carotenoids
the initial incorporation of carbon from CO2 into an organic compound by an autotrophic organism (a plant, another photosynthetic organism, or a chemiautotrophic prokaryote)
carbon fixation
the entire spectrum of electromagnetic radiation ranging in wavelength from less than a nanometer to more than a kilometer
electromagnetic spectrum
a stack of membrane-bound thylakoids in the chloroplast
grana
organisms that obtain organic food molecules by eating other organisms or substances derived from them
heterotrophs
a route of electron flow during the light reactions of photosynthesis that involves both photosystems and produces ATP, NADPH, and O2
linear electron flow
the first of two major stages in photosynthesis (preceding the Calvin cycle); occur on the thylakoids membranes of the chloroplast or on membranes of certain prokaryotes, converting solar energy to the chemical energy of ATP and NADPH, releasing oxygen in the process
light reactions
in C4 plants, a type of loosely arranged photosynthetic cell located between the bundle sheath and the leaf surface
mesophyll cells
the ground tissue of a leaf, sandwiched between the upper and lower epidermis and specialized for photosynthesis
mesophyll
nicotinamide adenine dinucleotide phosphate; an electron acceptor that temporarily stores energized electrons produced during the light reactions
NADP+
a metabolic pathway that consumes oxygen and ATP, releases carbon dioxide, and decreases photosynthetic output
photorespiration
the conversion of light energy to chemical energy that is stored in sugars or other organic compounds; occurs in plants, algae, and certain prokaryotes
photosynthesis
a light-capturing unit located in the thylakoid membrane of the chloroplast or in the membrane of some prokaryotes, consisting of a reaction-center complex surrounded by numerous light-harvesting complexes
photosystem
one of two light-capturing units in a chloroplast’s thylakoid membrane or in the membrane of some prokaryotes; it has two molecules of P700 chlorophyll a at its reaction center
photosystem I
one of two light-capturing units in a chloroplast’s thylakoid membrane or in the membrane of some prokaryotes; it has two molecules of P680 chlorophyll a at its reaction center
photosystem II
the process of generating ATP from ADP and phosphate by means of a proton-motive force generated across the membrane of the chloroplast or the membrane of certain prokaryotes during the light reactions of photosynthesis
photophosphorylation
quantums, or discrete quantities, of light energy that behave as if they were a particle
photons
microscopic pores surrounded by guard cells in the epidermis of leaves and stems that allow gas exchange between the environment and the interior of the plant
stomata
the dense fluid of the chloroplast surrounding the thylakoid membrane
stroma
an instrument that measures the proportions of light of different wavelengths absorbed and transmitted by a pigment solution
spectrophotometer
flattened membranous sacs inside a chloroplast; contain the “molecular machinery” used to convert light energy to chemical energy
thylakoids
that portion of the electromagnetic spectrum that can be detected as various colors by the human eye, ranging in wavelength from about 380 nm to about 750 nm
visible light
the distance between crests of waves, such as those of the electromagnetic spectrum
wavelength
in this process, carbon dioxide entering open stomata during the night is converted to organic acids, which release CO2 for the Calvin cycle during the day, when stomata are closed
CAM pathway
the range of a pigment’s ability to absorb various wavelengths of light
absorption spectrum
