Photosynthesis quiz Flashcards
Photosynthesis equation
6CO2 + 6H20 + light —> C6H12012 + 602
autotrophs
an organism that makes its OWN food
heterotrophs
consumers- must eat organic material
what organelle does photosynthesis occur in?
chloroplasts
what part of the plant is the major site for photosynth?
leaves - they are greenest part of the plant meaning they contain the most chlorophyll which is in chloroplasts
are chloroplasts double-membraned?
yes!
thylakoids
discs that contain chlorophyll - are the site of light reactions-
stack of thylakoids…
grana/granum
stroma
liquid inside a chloroplast - site of calvin cycle
names of 2nd part of photosynthesis
calvin cycle, dark reactions, light-independent reactions
chlorophyll
green pigment in thylakoids that captures light
palisade mesophyll
UPPER part of a leaf; majority of photosynth. happens here
stomata
opening in leaf that allows CO2 in and O2 out (also water)
when does a stomata close?
in high temperatures to avoid losing water
what parts of the photosynthesis equation are in dark reactions?
6CO2 in —> G3P —> C6H12O6 (glucose)
what parts of the photosynth. equation are apart of the light reactions?
6H20 —> in and 6O2 out
Can humans see absorbed light?
No- we can only see reflected light
how many types of chloroplast pigments are there?
4
chlorophyll a
bright green - absorbs blue and red light and participates DIRECTLY in photosynth.
chlorophyll b
dark green - absorbs blue and orange light and increases the range of light that can be absorbed
carotenoids
yellow/orange - absorbs blue-green light and dissipates excess light to protect chlorophyll a
anthocyanin
red, pink, blue, purple- absorbs blue-green light, absorbs light, and attracts pollinators
photon
fixed quantity of light energy that excites electrons in light reactions
photosystems
cluster of pigment molecules that attract photons
what color do leaves absorb the most?
red and blue
light reactions
absorbs solar energy to be converted to ATP and NADPH and O2 as a byproduct
light reaction step 1
protons hit chlorophyll in PS2 –> excite electrons
light reactions- what happens after electrons are excited?
electrons travel down electron transport chain
light reactions - PS2 function
PS2 splits water to replace electrons (H+ and oxygen)
light reactions - as the electrons move down ETC, what is their energy being used for?
electron’s energy is used to pump H+ to thylakoid space
light reactions- what direction do H+ ions go?
H+ move to stroma (high to low) via ATP synthase
light reactions- how is ATP produced?
ATP synth. rotates with H+ ions and produces ATP
light reactions- what does PS1 do?
PS1 excites electrons and makes NADPH
light reactions- what is the energy in the excited electrons used for after PS1?
electrons used to reduce NADP+ to NADPH (an electron carrier)
Calvin cycle- Carbon Fixation
RuBis Co (an enzyme) attaches the 5-carbon molecule RUBP to a one-carbon molecule CO2 —> forms 2 molecules of 3-phosphoglycerate
Calvin cycle - reduction
each 3-phosphoglycerate is reduced to form G3P (uses energy from ATP and electrons from NADPH)
Phase 3 - regeneration
one molecule of G3P will leave to form sugars and the rest will be recycled to form RUBP
photosystem 2
water-splitting
photosystem 1
NADPH producing
