Photosynthesis

stroma

central liquid space within chloroplast, contains enzymes to reduce CO2 to carbohydrates

chlorophyll

pigment in green plants: absorbs light in photosynthesis to reflect green

chloroplasts

organelles carrying out photosynthesis, located in the middle of a plant’s leaves

thylakoid

membrane-bound structures within chloroplasts where the light-dependent reactions of photosynthesis occur; contain chlorophyll

grana

stacks of thylakoid membranes

stomata

pores on the surface of leaves, allow CO2 to ENTER and O2 to EXIT

photosystem II

first protein complex, generates ATP

6 CO2 + 6 H2O + solar energy —> 1 C6H12O6 + 6 O2

photosynthesis equation

photolysis

splits water (H2O) into H+ ions, electrons (e-), and oxygen (O2)

thylakoid membranes contain:

chlorophylls, other pigments, protein carriers

light-dependent reactions

convert solar energy into chemical energy in the form of NADPH and ATP

where do light-dependent reactions occur

thylakoid space

where does photolysis occur

chloroplast (granum)

light-independent reactions (Calvin cycle)

NADPH and ATP produced and used to reduce CO2 into sugar

how many times does the Calvin cycle repeat

6

photosystem I

second protein complex, generates NADPH

how do plants produce ATP into the night

cellular respiration

rubisco

enzyme that attaches carbon to an organic molecule to generate G3P during the calvin cycle

why is chlorophyll green

reflects green light, absorbs red and blue

carbon fixation

incorporation of carbon into organic compounds, later being reduced to a carbohydrate

when does carbon fixation occur

during the calvin cycle

what makes up a photosystem

a reaction-center complex surrounded by several light-harvesting complexes

what is a reaction-center complex

association of proteins holding a special pair of chlorophyll a molecules and a primary electron acceptor

what is a light-harvesting complex

consists of various pigment molecules bound to proteins. proteins holding chlorophyll pigments and other accessory pigments absorb a broader spectrum of colors all together

carotenoids

accessory pigments that are shades of yellow and orange, absorb violet and blue-green light. these pigments broaden the colors able to be absorbed by photosystems

what are photons

particles with a fixed quantity of energy

function of photons during photosynthesis

excite electrons to a higher energy level through energy transfer

how many times does the calvin cycle occur per G3P molecule

3

first phase of sugar production

carbon fixation: CO2 attached to RuBP, results in 2 3-phosphoglycerate

second phase of sugar production

reduction: 3-phosphoglycerate receives phosphate group from ATP, and NADPH reduces the product into G3P

third phase of sugar production

regeneration of RuBP: 5 molecules of G3P rearranged into 3 RuBP, spending 3 ATP while the light reactions regenerate ATP. G3P is starting point for synthesis of molecules like glucose

how many G3P synthesize 1 glucose

2

light-dependent reactions

convert solar energy to chemical energy

light-independent reactions

convert chemical energy (ATP, NADPH) into sugar

what is the purpose of NADPH

carries the captured energy after being reduced into NADPH to the light-independent reactions, reducing an electron acceptor and providing energy, thus allowing CO2 to be reduced into G3P

antennae pigments function

gather more light than just blue/red to transfer to reaction center

examples of antennae pigments

chlorophyll b, carotenoids

where are the ATP synthase complexes located in a plant cell

thylakoid membrane and plasma membrane