lecture 19 part 1 Flashcards
why do most leaves appear green to us
because chlorophyll reflects green (we see reflected color)
where is chlorophyll found
leaves
chlorophyll are in chloroplasts in membranes that form thylakoids
4 things that happen during light rxns of photosynthesis
1)make ATP using photophosphorylation
2) split H2O
3)O2 is released
4)reduce NADP+ to NADPH
organisms that perform photosysnthesi
plants
-multicellular algae
-cyanobacteria
-purple sulfur bacteria
-universal eukkaryotes (ie phytoplankton)
photoautotrophs
produce their own food (chem energy) using light energy
primary producers make
food for primary consumers
why do plants perform photosyetsis
to make compounds necessary for cellular respiration and for making new bio moleqs
plants do both
cellular respiration and photosynthesis
where are chloroplasts found
mainly in cells of the mesophyll, the interior tissue of the leaf
how many chloorplasts do mesophyll contain
30-40
thylakoid membranes are location of
pigments and enzymes that capture light energy and convert it into chem energy (ATP + NADPH)
stroma
location of enzymes that bind CO2 and convert it into sugar
granum
stack of thylakoids
space inside of cell (like what cytosol would be but in chloroplast
stroma
describe the light rxn in thylakoid membranes
-split H2O
-release O2
-reduce e- acceptor NADP+ to NADPH
-generate ATP from ADP and Pi by photophosphorylation
does calcin cycle require light
yes but indirectly
calvin cycle happens in
stroma
describe calvin cycle
-forms sugar from CO2 using ATP + NADPH
-begins with carbon fixation incorporating CO2 into organic moleqs
overall photosyntesis rxn, what is reduced, what is oxidized
energy + 6CO2 + 6H2O -> C6H12O6 + 6O2
reduced: CO2 -> C6H12O6
oxidized: H2O -> O2
light is a form of
electromagnetic energy
light travels in ______ waves
rhythmic
wavelenth is
distance between crests and waves
light also behaves as though it consists of discrete particles called
photons
pigments are
substances that absorb visible light
different pigments absorb different
wavelengths
wavelnegths that are not absorbed are
relfected or trasnmitted
we see light that is
relfected or transmitted
white =
all relfected
black =
all absrobed
types of photosynthetic pigment
chlorophyll a + b
chlorophyll a is
three main photosynthetic pigment
chlorophyll b
broadens the light spectrum used for photosyntheis
difference between chlorophyll a + b
difference in absorption spectrum is due to a slight structural differnce between the pigment molecules
cartenoids are what type of pigment
yellow-orange pigments
cartenoids are
accessory pigemnts
what do carternoids do
absorb light for photosynthesis (minor role compared to chlorophyll)
-absorb excessive light that would be damaged chlorophyll (important job)
