Ch 10: Photosynthesis Flashcards
What are autotrophs?
“self-feeders” that sustain themselves without eating anything from other organisms, ex. plants
What is photosynthesis?
the process that converts solar energy into chemical energy within chloroplasts
What are heterotrophs?
they obtain organic material from other organisms; they are the consumers of the biosphere
What are chloroplasts?
an organelle in plants and other photosynthetic organisms found in the mesophyll
What is a mesophyll?
the interior tissue of a leaf where the chloroplasts are found
What is a stomata?
microscopic pores that CO2 enters and O2 exits the leaf through
What is the stroma in a chloroplast?
the dense fluid that is surrounded by two membranes
What are thylakoids in a chloroplast?
connected sacs that compose a third membrane system
What is chlorophyll in chloroplasts?
the pigment that gives leaves their green colo, resides in the thylakoid membranes
What is the equation of photosynthesis?
6 CO2 + 12 H2O + Light energy —> C6H12O6 + 6 O2 + 6 H2O
How is photosynthesis a redox process?
H2O is oxidized and CO2 is reduced
What are the two stages of photosynthesis?
light reactions (the photo part) and the Calvin cycle (the synthesis part)
What is the light reaction in photosynthesis?
in the thylakoids, split H2O, providing electrons and protons (H+), release O2 as a by-product, reduce the electron acceptor NADP+ to NADPH, and generate ATP from ADP by photophosphorylation
What is the Calvin cycle in photosynthesis?
in the stroma, makes sugar from CO2, using ATP and NADPH generated during the light reactions
What is a wavelength?
a measure of the distance between crests of electromagnetic waves ranging from a nanometer to a kilometer
What is the electromagnetic spectrum?
the entire range of electromagnetic energy, or radiation
What is visible light
wavelength from 380 nm to 740 nm, it drives photosynthesis and produces the colors seen by the human eye
What is a photon?
a light particle which has a foxed quantity of energy
What are pigments?
substances that absorb visible light
What is a spectrophotometer?
measures a pigment’s ability to absorb various wavelengths–it sends light through pigments and measures the fraction of light transmitted at each wavelength
What is an absorption spectrum?
a graph plotting a pigment’s light absorption versus wavelength
What are the three types of pigments in chloroplasts?
chlorophyll a, chlorophyll b, and carotenoids
What is chlorophyll a?
the key light-capturing pigment that participates directly in light reactions
What is chlorophyll b?
an accessory pigment