BIOL 141 Lecture Notes - Lecture 21: Light-Independent Reactions, Periplasm, Accessory Pigment
Monday, December 4, 2017
BIOL141
•Chemiosmosis - a membrane is required to have a gradient, prokaryotes’ is on the
plasma membrane - concentration gradient between periplasmic space and
cytoplasm, cell wall can surround this periplasmic space and is more effective in
terms of the protons being kept together in an enclosed space#
•Autotroph (able to form nutritional organic substances from simple inorganic
substances) vs heterotroph (derives its nutritional requirements from complex organic
substances)#
•Obligate - has to have that condition (zorunlu aerob/zorunlu anaerob)#
•Facultative - could live in either/both#
•Some bacteria use sulfur and nitrates instead of oxygen#
•Cellular respiration can produce more energy when oxygen is the final e acceptor (the
change in potential energy is the largest)#
•Photosynthetic plants are green - chlorophyll absorbs light at the ends of the visible
spectrum#
•Autotrophs can use different photopigments - accessory pigments like carotenoids#
•In photosynthesis, carbon is reduced and oxygen is oxidized #
•Needed for photosynthesis: water, CO2 and light#
•The water primarily comes from soils and is transported through the doors, CO2 is
taken from the air through the pores#
•The internal membranes of chloroplasts form flattened, vesicle-like structures called
thylakoids, some of which form stacks called grana (singular granum)#
•Thylakoid membranes contain large quantities of photo reactive pigments (eg
chlorophyll)#
•The fluid space between the thylakoids and inner membrane is called the storm#
•Two pathways for photosynthesis:#
•Light capturing reaction: driven by light energy captured by chlorophyll. It produces
ATP and NADPH#
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