Unit 4: Energy Processes Flashcards
mesophyll
tissue in the interior of the leaf in which chloroplasts are mainly found
stomata
microscopic pores on a leaf. Allow CO2 to enter and oxygen to exit
veins
deliver water from roots to leaves and export sugar from leaves
chlorophyll
a green pigment that resides in thylakoid membranes of plants
-absorbs light energy
Formula of Photosynthesis
6CO2+ 6H20+Energy – C6H1206+ 6O2
-endergonic
light reactions
the steps of photosynthesis that convert solar energy to chemical energy (ATP and NADPH)
- water is split, providing electrons, H+, and 02
- absorbed light drives the transfer of electrons and H+ from water to NADP+
Calvin Cycle
carbon is fixated, incorporated into an organic molecule, Calvin cycle adds electrons, reducing fixed carbon to a carbohydrate
-occurs in the stroma
Light used in photosynthesis
380nm to 750 nm (visible light) drive photosynthesis
-chlorophyll absorbs violet-blue and red light, reflects green
photons
discrete particles of light, explains many of light’s properties
-shorter the wavelength, the greater the energy of each wavelength
pigments
substances that absorb light
chlorophyll a
pigment that participates directly in light reactions
chlorophyll b
an accessory pigment, broadens the spectre of colors that can by used for photosynthesis
carotenoids
a group of accessory pigments
- hydrocarbons, that are usually yellow or orange
- absorb and dissipate excessive light energy which could cause damage
photosystem
composed of a reaction-center complex surrounded by several light-harvesting complexes
reaction-center complex
an organized association of proteins holding a special pair a special pair of chlorophyll molecules
- in PSII; P680 pigments
- in PSI- P700 pigments
light harvesting complex
-various pigment molecules bound to proteins
Linear Electron Flow
flow of electrons through the photosystems and other molecular components built into the thylakoid membrane
Cyclic Electron Flow
an electron path that uses PSI but not PSII
- electrons cycle back fro the primary accpetor, to ferredoxin, to the cytochrome complex, to plastocyanin
- their is no production of NADPH or O2 but does release ATP
