chapter 10 Flashcards
autotrophs
producers “self feeders”
photoautotrophes
use sunlight to make food
heterotrophs
consumers
get energy from other organism
chloroplast
site of photosynthesis
mesophyll cells
internal cells in chloroplasts where photosynthesis occures
stomata
tiny pores in the leaf that plants can open and close base on environmental conditions
stroma
dense fluid in the chloroplasts
thylakoids
connected sacs in the chloroplast that composes a third membrane system
thylakoid space
space inside the thylakoid membrane
chlorophyll
pigment that makes plants green
what is oxidized in photosynthesis and what is reduces
H2O oxidized
CO2 reduced
is photosynthesis endergonic or exergonic reaction
endergonic
parts of photosynthesis
light reactions and Calvin cycle
steps of light reactions
get electrons and H+ from splitting H2O
release O2
Reduce the electron acceptor from NADP+ to NADPH
get ATP from ADP by phosphorylation
what does the calvin cycle do
makes sugar from CO2 using the ATP and NADPH from light reactions
carbon fixation
incorporating CO2 into organic molecules (start of calvin cycle)
where does the calvin cycle happen
in the stroma
where do the light reactions happen
thylakoid
wavelength
distance between the crests of electromagnetic waves
electromagnetic spectrum
the range of electromagnetic energy or radiation
visible light
wavelengths 380 nm to 740 nm
colors seen by the human eye
photons
partial of light
pigments
absorb visible light
spectrophotometer
measures a pigment’s ability to absorb various wavelength
chlorophyll a
the key light capturing pigment that participates directly in light reactions
chlorophyll b
accessory pigment
action spectrum
a profile of relative effectiveness of different wavelengths
why is the absorbable different between chlorophyll a and b
the structure is slightly different
carotenoids
yellow or orange accessory pigments that absorb violet and blue-green light
photosystem
has a reaction-center complex surrounded by light harvesting complexes
reaction-center complex
an association of proteins holding a special pair of chlorophyll a molecules and a primary electron acceptor
light harvesting complex
has various pigment molecules bound to proteins
primary electron acceptor
in the reaction center accepts excited electrons and is reduced as a result
photosystem II (PSII)
(1st) called P680
its reaction-center chlorophyll is best at absorbing light
photosystem I (PSI)
(best at absorbing light with a wavelength of 700
linear electron flow
the primary pathway, involves both photosystem and produces atp and NADH using light energy
cyclic electron flow
excited electrons cycle back from Fd to cytochrome complex instead of being transferred to NADP+
- produces extra atp but no oxygen
what side is ATP and NAPH made in photosynthesis
stroma side of the thylakoid membrane (making them availible in the calvin cycle)
is the calvin cycle catabolic or anabolic
anabolic because it bilds sugars from smaller molecules
how does carbon enter the calvincycle
CO2
how does carbon leave the calvin cycle
glyceraldehyde 3-phosphate (G3P)
how many turns in the calvin cycyle to make G3P
3
phase 1 of calvin cycle
carbon fixation
carbon fixation
binding CO2 to a five-carbon sugar which is catalyzed by rubisco
- six carbon molecule is split into two 3-phosphoglycerate
reduction
-Each molecule of 3-phosphoglycerate is phosphorylated by ATP and reduction by NADPH to ultimately produce a G3P sugar
- For every three CO2 molecules that enter the cycle, six molecules of G3P are formed
-Only one of these can be counted as a net gain of carbohydrate
regeneration of CO2 acceptor
-The remaining five molecules of G3P are rearranged in a complex series of reactions yielding three molecules of RuBP
-Three additional molecules of ATP are used to facilitate the regeneration of RuBP
for one G3P how many atp and nadph are needed?
9 atp and 6 nadph
what happens when it is hot and dry to plants
close stomata to conserve H2Obut limits photosynthesis
photorespiration
plat closing stomata and reducing acess to CO2 and building up O2
C3 plants
the initial fixation of CO2, via rubisco, forms a three carbon compound (most plants)
photorespiration
rubisco binds to O2 instead of CO2 producing a two carbon compound
why is photorespiration bad
t consumes O2 and organic fuel withought making atp
how much energy is being wasted through photorespiration
50%
C4 plants
take CO2 and make a 4 carbon compund then release CO2 when it is needed to make rubisco work better
which uses less water C4 or C3 plants
c4
how many G3P in glucose?
2
