Studied by 16 peoplelight-harvesting complexes
proteins with molecules bound to them that function as a light-gathering antenna
The Calvin Cycle
occurs in the stroma of the chloroplast and is a series of reactions that assembles sugar using CO2 and products of the light reaction
CAM plants
only admit CO2 at night and saves it so the plant can use it during the day, when the stomata are closed
Rubisco
thought to be the most abundant protein on Earth and is the enzyme that attaches CO2 to RuBP during carbon fixation
C4 Plants
fixes CO2 into a 4 carbon compound during carbon fixation, the Calvin Cycle happens in a different kind of cell to conserve CO2
RuBP
a five-carbon sugar and is the starting material needed for the Calvin Cycle
The Calvin Cycle
like the sugar factory of the cell and occurs in the stroma, produces NADP+, ADP, G3P, and RuBP. The reactants are NADPH, ATP, CO2 and RuBP and it
Light Reactions
the reactions that convert light energy to chemical energy and occurs in the thylakoid membranes
carbon fixation
The incorporation of carbon from CO2 into organic compounds and is a step in the Calvin Cycle
Chlorophyll a
a pigment in the chloroplasts that absorbs mainly blue-violet and red light, and reflects green light
Chlorophyll b
absorbs mainly blue and orange light and reflects yellow and green light. It also broadens the range of light a plant can use
carotenoids
other pigments found in chloroplasts and are various shades of yellow and orange
photoprotection
a function of carotenoids, where they absorb and dissipate excess light that would otherwise damage the chlorophyll
photosynthesis equation
6CO2+6H20 →C6H12O6 +6O2
photosynthesis
the process of converting light energy to chemical energy
autotrophs
plants that make their own food and sustain themselves without consuming organic molecules derived from other organisms
photoautotrophs
plants that catch light energy and convert it to chemical energy and are the ultimate source for all other organisms
endosymbiotic theory
states chloroplasts originated from a photosynthetic prokaryote that took up residence in a eukaryotic cell
chlorophyll
the light absorbing pigment in the chloroplast
mesophyll
the green tissue in the interior of the leaf where the chloroplasts are found
stomata
the “pores” of a cell that allows CO2 and O2 to enter and exit the cell
veins
how water and sugar are moved within the plant
30-40
the amount of chloroplasts in one mesophyll cell
stroma
the thick liquid between the inner and outer membrane
thylakoid space
an internal compartment inside of thylakoids
thylakoid
a system of interconnected membraneous sacs found in the stroma, that looks like a pancake
grana/granum
the name of the stacks of thylakoids
photosystem
a number of light-harvesting complexes and a reaction-center complex
fluoresence
the photons of light that are given off during photosynthesis
chemiosmosis
the energy given off from the ETC causes the H+ gradient to form, and drives cellular work
photophosphorylation
the production of ATP during photosynthesis
heterotrophs
consumes other plants/animals/decomposed organic material
Chemical bonds of sugar molecules
where plants store their chemical energy
C3 plants
a plant that takes CO2 from the atmosphere and fixes it into a 3 carbon compound
photorespiration
when O2 builds up in a leaf and Rubisco adds O2 to RuBP instead of CO2 and yeilds no sugar
G3P
a product of the Calvin Cycle needed to make glucose and other organic compounds, and is 1/2 of a glucose molecule
reaction-center complex
contains the pair of special chlorophyll a molecules and the primary electron acceptor which accepts an electron from a split up water
What happens during the first step, carbon fixation, of the Calvin Cycle?
the enzyme rubisco attaches CO2 to RuBP, which splits into two molecules of 3-PGA
What is NADPH used for in the Calvin cycle?
NADPH provides the electrons for the further reduction of carbons in the Calvin Cycle
What is oxidized in photosynthesis?
6 H2O
How do the reactant molecules of photosynthesis reach the chloroplasts in leaves?
O2 and CO2- the stomata
H20- the roots
Where is chlorophyll found? (be specific)
the thylakoid membranes
Why would you expect photorespiration on a hot, dry, day to occur less in C4 and CAM plans than in C3 plants?
Because C4 and CAM plants have their carbons fxed in a way that would ensure they have enough for photosynthesis without having to take in more through their stomata
To synthesize one glucose molecule, the Calvin Cycle uses CO2, ATP, and NADPH.
6 CO2
18 ATP
12 NADPH
What happens during the third step of the Calvin Cycle?
1 G3P leaves the cycle, which is the net product of photosynthesis. The remaining 5 G3P are brought to RuBP regeneration
For every 3 CO2 that enters the cell how much 3-PGA is made?
For every 3 CO2 that enters 6 3-PGA are made
What’s the difference between oxidative phosphorylation in cellular respiration and photophosphorylation in photosynthesis?
The electrons used for oxidative phosphorylation are from oxidised organic molecules and passed down the ETC and for photophosphorylation the electrons come from the splitting of water
What is an advantage of the light reactions producing NADPH and ATP on the stroma side of the thylakoid membrane?
NADPH and ATP are reactants of the Calvin Cycle, which occurs in the stroma
Which redox process is endergonic, photosynthesis or cellular respiration?
photosynthesis
What is ATP used for in the Calvin Cycle?
ATP produced in the light reactions is used to power several steps of the Calvin Cycle
What do self-feeding photoautotrpohs require from the environment in order to make their own food?
Light, CO2, and H2O
What are the other names of the Calvin Cycle?
The light-independent reaction or dark reaction
For Chloroplasts to produce sugar from CO2 in the dark, they would need to be supplied with __ and ___
NADPH and ATP
What is oxidized in cellular respiration?
C6H12O6
Why is the Calvin Cycle called a “Cycle”?
Because the starting material is regenerated with every turn of the cycle
What is reduced in cellular respiration?
6 O2
What are the products of the light reactions?
NADPH, ATP, and O2
What happens during step four of the Calvin Cycle?
RuBP is regenerated through a series of chemical reactions that use ATP to rearrange the atoms in the 5 G3P
Note
Flashcard