chapter eight + ten Flashcards
introduction to metabolism and photosynthesis
metabolism
chemical reactions in the body’s cells that change food into energy, interactions between molecules
anabolic pathways
consume energy to build larger molecules, uphill
catabolic pathways
release energy by breaking down complex molecules to simpler pieces, downhill
bioenergetics
the study of the flow of energy in living organisms
energy
cause change and do work
if delta G is greater than 0, then ?
products have more energy than reactants
if delta G is less than 0, then ?
reactants have more energy than products
exergonic reaction
energy released, spontaneous, delta G is negative
what is an example of an exergonic reaction?
cellular respiration; breaking down sugar and release energy
endergonic reaction
energy required, nonspontaneous, delta G is positive
what is an example of an endergonic reaction?
photosynthesis; building sugar and storing energy
autotrophs
make their energy themselves
example of autotrophs?
plants, algae, bacteria
photoautotrophs
use sunlight
chemoautotrophs
other chemical reactions that use chemicals to make sugar
heterotrophs
need to consume energy
chloroplast
in the mesophyll layers near the surface of the leaf
cuticle
waxy surface coating
mesophyll
two layers that go through photosynthesis
stomata
openings on the bottom side of the leaf that let gases diffuse in and out
vascular bundle
veins that bring in water and nutrients and dispose waste
thylakoid membrane
where photosynthesis reactions take place
stroma
space outside thylakoid but within chloroplasts
OIL
oxidation is losing electrons and H+
RIG
reduction is gaining electrons and H+
light reactions
take in sunlight, use water and produce O2
calvin cycle
uses CO2x, ATP and NADPH from light reactions to make sugar
black light
absorbs all colors and reflects none
white light
reflects all colors and absorbs none
green light
reflects green and absorbs all other colors
step one: photosystem ii
light is absorbed and H2O is broken up
step two: photosystem i
light is absorbed and reexcites the electrons that travel to it from pii
non cyclic electron flow
not solo, photosystem 1 and 2 working together
cyclic electron flow
solo, photosystem 1 working independently to pump protons
photorespiration
light and O2 instead of CO2 in the calvin cycle; rubisco works with whichever is more prevelant, occurs when co2 levels are low and o2 are high
C4 plants
live in areas that can be dry at times and go through droughts, stomata is partially closed to prevent water loss, limits gas exchange
CAM plants
highly modified for extremely hot/dry areas, completely close stomata during the day and only open at night, ex: cacti, pineapple
activation energy
energy needed to start a reaction
transition state
the point where the reactants bonds are unstable and about to be broken
visible spectrum
white light splits up into all the colors of a rainbow
chemiosmosis
flow of electrons with the gradient to make ATP
mesophyll cells
pepcarbox fires co2 - no calvin cycle
bundle sheath cells
rubisco fires co2 - calvin cycle
