08-photosynthesis

1. introduction -CC nutritional modes -SEQ, HD light and electrons 2. structures -DRAW, CC components 3. process -DRAW, CC PSI and PSII -SEQ, CC, HD light dependent reactions and Calvin cycle

What is the equation for photosynthesis?

6CO2 + 6H2O + light energy = C6H12O6 + 6O2.

what are the nutritional modes in photosynthesis?

autotrophs and heterotrophs

autotrophs

Organisms that make their own food

heterotrophs

Organisms that depend on other organisms for their food

what is the effect of photons on electrons?

1. molecules are absorbed with light energy

2. electrons are energized (unstable)

3. returns to ground state AND electron leaves atom and is captured by acceptor (photosynthesis)

why are so many leaves green?

light shines down through chloroplast to a granum, that absorbs the light and remits the light out, giving a leaf it's green color

nature of light

a form of electromagnetic energy with properties of particles and waves

shorter wavelength =

higher energy

longer wavelength =

lower energy

what is the primary eukaryotic photosynthetic organelle?

chloroplast

photosynthetic pigments

Chemicals that absorb light energy and use it to carry out photosynthesis. Contained in thylakoid membranes in chloroplast. Examples are chlorophyll a, chlorophyll b

PS1

produces NADPH, P700, Chlorophyll B, happens after PS2, absorbs light energy

PS2

P680, Chlorophyll A, happens before PS1, absorbs light energy

PS2 and PS1

- PQH2 diffuses to thylakoid membrane and binds cytochrome b6f donating 2 e-s

- 2 H+ released to lumen and 2 H+ translocated in

- cytochrome b6f transfers electrons to plastocyanin (contains Cu)

- plastocyanin carries to luminal side of PS1 and transfers to P700+

Linear Electron Flow

the primary pathway, involves both photosystems and produces ATP and NADPH using light energy

cyclical electron flow

Photosystem I can transport electrons in cyclical fashion- no NADPH is produced, but a proton gradient and ATP

light dependent reaction

first stage of photosynthesis where certain wavelengths of the visible light are absorbed to form two energy-carrying molecules (ATP and NADPH)

Calvin Cycle

light-independent reactions of photosynthesis in which energy from ATP and NADPH is used to build high-energy compounds such as sugar

Carbon Fixation (Calvin Cycle)

Three molecules of carbon dioxide are added to three molecules of a five-carbon sugar abbreviated RuBP. These molecules are then rearranged to form six molecules called 3-PGA, which have three carbons each.

Reduction (Calvin Cycle)

PGA is converted to G3P with high energy electrons from NADPH and energy from ATP

Regeneration (Calvin Cycle)

5 G3P + 3 ATP --> 3 RuBP

Where do the light-dependent reactions take place?

thylakoid membrane

Where does the Calvin cycle take place?

stroma

what is the output of light dependent reactions?

O2, ATP, NADPH

what is the output of the Calvin cycle?

glucose, ADP, NADP+, Pi, H20