Unit 3 – Lecture 8

PhotosynthesisPhotosynthesis: the process used by

autotrophs which changes solar energy, water [H2O], and carbon dioxide [CO2] into glucose [C6H12O6] and oxygen [O2]

Equation for Photosynthesis: E + H2O +CO2 C6H12O6 + O2

Photosynthesis – cont’dtakes place in the chloroplasts of the cell

“chloro” – green [pale green]contain green pigment, chlorophyll

“phyll / phyllos” = leafchloroplasts are FILLED with

chloroPHYLL

Light Dependent Reactionssunlight

transfers a photon of solar energy to

chlorophyll in the chloroplast

which exites an electron

e- gets knocked out of placement

Light Dependent Rxns – cont’de- travels down the Electron Transport Chain

[also called Electron Transport System]

as e- travels, it loses E

that E splits H2O [called photolysis] into

Oxygen [O2] Gas and Hydrogen [H+] Ions

which is released into the atmosphere

Light Dependent Rxns – cont’d… Hydrogen [H+] Ions…

which either

bonds with NADP+ is pumped into the thylakoid

to form NADPH

to form a gradient of which goes to the light charge AND independent reactions concentration

[called electrochemical

gradient]

Light Dependent Rxns – cont’d…ElectroChemical Gradient…

which causes the H+ ions to funnel through

the ATP Synthase

to form a small amountof ATP

Light Dependent Rxns – cont’d…to form a small amount of ATP…

which goes on to the Light Independent Reactions

Summing it up…Equation: E + H2O +CO2 C6H12O6 + O2

of the things in our equation…which things are input or formed in the light dependent reactions of photosynthesis?input: energy + water formed: oxygen gas

ATP SynthaseHydrogen Ions are pumped into the thylakoid

membrane after water is split…ions form electro-

chemical gradientions funnel through

ATP synthaseturns “crank”

energy from turningmakes ADP+P intoATP

Light Independent Reactionsaka Dark Reactions or Calvin Cycle

can occur in the LIGHT or the dark[light rxns can only occur when there is

sunlight]

The Calvin Cycle

Light Indep. Rxns – cont’dWhat you NEED to know:

can occur with or without light presentcomposed of the calvin cycleCarbon dioxide (CO2) is taken in and

combined with the H+ from NADPH (using ATP) to make Glucose (C6H12O6).

leftovers – ADP and NADP+ go back to light dependent reactions

Summing it up…Equation: E + H2O +CO2 C6H12O6 + O2

of the things in our equation…which things are input or formed in the light INdependent reactions of photosynthesis?input: carbon dioxide [and some water]formed: glucose

Overview - Photosynthesissolar

energy [photon]

ATP

NADPH

NADP+

ADP

H2O

a little bit of H2O

CO2

O2

C6H12O6

thylakoids

stroma

IMPORTANT!!Be sure to know:

what goes inwhere that came from

what goes outwhere that’s going