LO9 Flashcards
light travels from the sun to earth in _________
waves
sunlight consists of energy waves called _________
photons
photons with shorter wavelengths have ______ energy
more
photosynthesis required photons in the _____ range
visible
when molecules absorb photons a __________ become energized
valence electron
definition: molecules that get excited by light
pigments
_______________ pigments are embedded in the ___________- of chloroplasts in plants and algae
photosynthetic; thylakoid membranes
pigments that absorb blue and red light
chlorophylls a and b
chlorophylls a and b reflect ____ light
green
absorb blue light and reflect red and orange
carotenoids
chlorophyll molecules have a 2-part structure
- porphyrin ring
- hydrocarbon tail
the porphyrin ring in the chlorophyll molecule does what?
absorb light
the hydrocarbon tail in the chlorophyll molecule does what?
anchors the molecule in the thylakoid membrane
photosynthesis is ____ and ______
anabolic; endergonic
summary equation of photosynthesis
6 CO2 + 6 H2O –> C6H12O6 + 6O2
in photosynthesis ____ energy is converted to _____ energy
light(kinetic); chemical(potential)
hydrogen atoms are _______ to form organic molecules
reduced
oxygen atoms from water are_______
oxidized
photosynthesis occurs in ___ phases
two
Phase 1 of Photosynthesis
- light dependent reactions require thylakoid membranes
- use light energy to generate ATP and NADPH
- produces oxygen
Phase 2 of Photosynthesis
- carbon fixation reactions
- use ATP and NADPH to form organic molecules
definition: process that takes the carbon in inorganic CO2 and incorporates it into organic molecules
carbon fixation
carbon fixation reactions occur in the _____
stroma
definition: collection of 1000s of pigment molecules + enzymes and other proeins
photosystem
pigments are in ________
photosystems
photosystems have a _________ that include two chlorophyll a molecules
reaction center
definition: only pigment that transfers electrons to electron carrier molecules when excited by light
chlorophyll a
chlorophyll a is the _____ photosynthetic pigement
primary
Chlorophyll b is the ______ photosynthetic pigment
secondary
Chlorophyll b, carotenoids and other secondary photosynthetic pigments do what?
pass energy to chlorphyll a
photosystem I (P____)
700
photosystem II (P____)
680
Photosystem I has a reaction center that gets most excited by
700 nm wavelength photons
Photosystem II has a reaction center that gets most excited by
680 nm wavelength photons
Begins when pigment molecules absorb photons
LDR
What happens when a pigment molecule absorbs a photon
energy is passed from one molecule to another until it reaches a photosystem reaction center
Photosystem I (700) and Photosystem II (680) have their own ____ that occur simultaneously
ETC
electrons from chlorophyll a become energized and are _______
transferred to a primary electron acceptor
electrons flow from the P700 reaction center through a series of electron carrier molecules to _______
ferredoxin
electrons flow from the P680 reaction center through a series of electron carrier molecules to _______
P700
Definition: an iron containing protein
ferredoxin
ferredoxin reduces_________
NADP+ –> NADPH
ferredoxin reduces NADP+ –> NADPH into the _____
stroma
definition: the final electron acceptor of photosynthesis
NADPH
electrons from _____ reaction center replace electrons lost from the ______ reaction center
P680; P700
photolysis of H2O yields ___ e- to replace those lost by the ______ reaction center
2; P680
a portion of the cytochrome complex functions as a ________
proton pump
synthesis of ATP by chemiosmosis and phosphorylation
- stroma –> thylakoid lumen
- thylakoid lumen –> to stroma through proton channel in ATP synthase
Calvin cycle converts ___ into _____ molecules
CO2; organic
calvin cycle requires ___ and ____ from the light dependent reaction
ATP;NADPH
Step 1: calvin cycle
- CO uptake phase fixes carbon
- CO2 reacts with 5-C RuBP to from 2 3-C PGA
-catalyzed by rubisco - carbon fixation has occured
Calvin cycle step 2: carbon ____ phase
reduction
during carbon reduction energy from ATP and NADPH is used to convert ____ to ____
PGA to G3P
_____ final product of calvin cycle
G3P
in calvin cycle 2 what is needed and what is formed?
- one glucose formed from 2 G3P
- 6 CO2 needed for net yield of 2 G3P
G3P can then be used by a _______
photoautotroph
G3P is used by a photoautotroph to make
- glucose or other simple sugars
- sucrose
- complex carbs
- amino acids and/or lipids
things made by photoautotroph can be broken down during cellular respiration to…?
make ATP or use as building blocks
calvin cycle step 3 known as
RuBP Regeneration Phase
in step 3 for every ____ CO2 molecule that enter ___ G3P are produced
6; 12
RuBP regeneration requires a ________ from ATP
phosphate group
