Photosynthesis

Autotrophs and Heterotrophs

• Autotrophs are organisms that make their own food

• Heterotrophs are organisms that need to ingest food to obtain energy

How are they related??

Autotrophs

Photosynthesis• How plants (and some other organisms) use

light to convert water and carbon dioxide into oxygen and sugar!

• Happens here = chloroplast

Leaf

Plant Cell

chloroplast

Chloroplasts have chlorophyll (pigment)

This is why chloroplasts are green, why leaves are green

Chloroplast

Lumen (inside thylakoid)

Outer membrane

intermembrane space

Inner membrane

Stroma

thlakoid

grana

Photosynthesis

Light reactions

Dark Reactions

Photosystem II

Photosystem IIn thylakoid membrane

(aka… The Calvin Cycle)In stroma

2 Photosystems in thylakoid

Light reactions

Light reactionsIn thylakoid membrane

P680

photons

P680

ETR

ATP

P700

P700

ETR

ATP

Photosystem II Photosystem I

NADPH

NOTE……

Electron Carriers are NADP …… b/c can become NADPH

• Hydrogen ions flow through a channel in the thylakoid membrane

• ATP synthase attachedto the channel makesATP

How ATP made in light rxn?