ch. 8 | photosynthesis Flashcards
from 8.1
what are the raw materials for photosynthesis? how do these materials enter plants?
- water; absorption via roots
- CO2; absorbed into stomata (openings in leaves)
from 8.1
CO2 & water diffuse into _____________
chloroplasts
from 8.1
the ________ is a fluid-filled space where CO2 is enzymatically red’d to CO2
stroma
from 8.1
membranous disks containing photosynthetic pigments in the chloroplasts are called?
what do these pigments do?
thykaloids
abosrb solar energy
from 8.1
carotenoids give photosynthesizing cells a _________ color
yellow to red
from 8.1
what are light reactions?
2 sets of reactiona; light-dependent reactions & Calvin cycle reactions (light-independent)
from 8.1
what are the functions of the 2 different types of reactions in photosynthesis?
- light reactions release O2
- Calvin cycle (independent) reactions reduce CO2 to a carb
from 8.1
this molecule carries hydrogen atoms from light reactions to Calvin cycle reactions
what is another function of this molecule?
NADP+
allows independent reactions to reduce CO2
from 8.1
light reactions require the input of light energy, resulting in the generation of _________
NADPH & ATP
from 8.2
the colors violet, indigo, blue, and red are absorbed by which pigments?
chlorophyll a & b
from 8.2
carotenoids aborb light in what part of the color spectrum?
**careful: ABSORB not GIVE OFF
violet to green
from 8.2
light reactions in the thykaloid membrane have 2 electron pathways called _________________. both pathways produce ATP, but which of the pathways also produces NADPH?
- noncyclic & cyclic electron pathways
- the noncyclic pathway
a ________ consists of a pigment complex (re: pigments in chloroplasts) & an acceptor in the thykaloid.
what is the function of the pigment complex?
photosystem
serves as an “antenna” for gathering solar energy
during the noncyclic electron pathway, energized electrons leave photosystem _____& pass down the ETC leading to the formation of ______
II; ATP
from 8.2
_________________ (replaced by PS* II) leave PS I & pass to NADP+ which combines w/ H+ & froms NADPH+
so PS I forms what?
*PS = photosystem
energized electrons
NADPH
from 8.2
the process of splitting what molcule provides replacement electrons to PS II?
(this releases H+ ions & oxygen)
water
from 8.2
energy released from electrons move H+ ions to from the stroma into the _________________ forming a hydrogen gradient
thykaloid space
the ETC carries electrons from which PS to which?
PS II to PS I
from 8.2
PS I is adjacent to __________ which redices NADP+ to NADPH
NADP reductase
from 8.2
the ATP synthase complex crosses the ___________ & contains an interior channel & protruding ATP synthase that joins ADP + P
thykaloid
from 8.2
under high oxygen levels, NADPH levels may accumulate in the cell, so photosynthetic cells can enter the _______________. what’s the difference between this & the noncyclic pathway?
cyclic electron pathway; electrons are recycled back to PS I (so it’s actually a CYCLE)
from 8.2
in the cyclic pathway, energized electrons are taken up by __________ & sent down an ETC. spent eletrons return to __________ after the ETC.
what function does this serve in the cyclic pathway?
an electron acceptor; PS I
this is how PS I receives replacement electrons
from 8.2
why is the H+ gradient across a thykaloid membrane called a storage of energy?
bc there are more H+ ions in the thykaloid space than in the stroma, ions tend to move down the gradient + release stored energy to fuel ATP synth
from 8.2
what is the reaction center?
a particular pair of chlorophyll a molecules. here is where electrons become so energized that they escape & move to acceptors
