Photosynthesis

Where do the light reactions of photosynthesis take place?

In the thylakoid membrane of the folded inner membrane of chloroplast

Stroma

The fluid part of the chloroplast where calvin cycle takes place

What pigment molecule is used by plants for photosynthesis?

Chlorophyll

What are the requirements for photosynthesis?

CO₂, H₂O, photons of light

What is a byproduct of photosynthesis?

Oxygen gas

What is a product of photosynthesis?

Glucose

Which color from the visible spectrum is least effective in driving photosynthesis?

Green

Which colors do plants use for photosynthesis?

Red and blue

What replaces the electrons lost by chlorophyll when light strikes it?

Electrons from splitting water molecules

What are produced by the light reactions to be used in the Calvin cycle?

ATP and NADPH

Autotrophs

Produce own food, photosynthesize

Ex. Plants

Heterotroph

Get food from another source, ingest food

Ex. Animals

electromagnetic spectrum

The entire range of radiation from the sun

Photons of energy measured in wavelengths

Visible spectrum

Part of electromagnetic spectrum

Seen as colors by the human eye

Chlorophyll absorbs red and blue light ( reflects green )

Photon

Waves of energy

Stomata

" little mouth" tiny opening on the leaf surface that allows co2 to enter and o2 to exit

Photosystem

A collection of chlorophyll molecules embedded on a protein in the thylakoid membrane

Chloroplasts

Membranous organelles in plants, site of photosynthesis

chlorophyll molecules

Pigment that responds to ( oxidized by) red and blue wavelengths of light

Photosynthetic organisms

Plants

Seaweed

Unicellular protists

Cyano bacteria

flow of energy

From sun as photons, to sugar, to ATP used by cells , finally lost as heat

NADP+

An electron carrier molecule will be reduced to NADPH

Equation for reduction of NADP+

NADP+ + 2e- +H into NADPH ( reaction will be reversed)

Behavior of light

Absorbed- utilized by the cell to run a chemical reaction

Reflected- bounced back

Transmitted - passes through

thylakoid space

Cycling of carbon

From CO2 to C6H12O6 and back

cycling of oxygen

From H2O to O2 and back

Cycling of hydrogen

From H2O to C6H12O6 and back

thylakoid space

Area inside thylakoid membrane

Grana

Green Stacks of thylakoid membrane

The Light Reactions (Photosystem 1)

Photons of light strike a chlorophyll molecule, 2 e- are excited and get caught (oxidized) by an e- acceptor and then used to make a small amount of ATP

Water is split by an enzyme and it 2e- are used to replace those lost from the chlorophyll

The Light Reactions (Photosystem 2)

Photons of light strike another chlorophyll molecule, 2e- are excited and are caught by NADP+ to form NADPH

NADP+ also picks up H+

The 2 e- used to make ATP eventually replace those lost from this chlorophyll

What is required for light reactions

Photons, water, chlorophyll

Where do light reactions occur?

Occur along the thylakoid membrane of the chloroplast

What is produced by light reactions

ATP and NADPH

O2 as a byproduct

Calvin Cycle = the "synthesis"

A series of steps where the carbon atoms are linked together

CO2 > C6H12O6 by adding e- and H+ from NADPH

Fueled by the ATP made during the light reactions

Where does the Calvin cycle take place?

Occurs in the stroma of the chloroplast

What is needed for calvin cycle

Requires NADPH and ATP from the light rxns

What does the Calvin Cycle produce?

Produces sugar