Light and Pigments
• Pigments – light
absorbing molecules
• Chlorophyll – the
most abundant
pigment in plants,
that absorbs blue
and red light.
Photosynthesis: An Overview
• Photosynthesis takes place in the
chloroplast
– Thylakoids – saclike photosynthetic
membrane in the chloroplast
– Stroma - the region outside of the
thylakoid membranes
Photosynthesis: An Overview
Photosynthesis is a complex process that can be broken
down into 2 steps:
Step 1: Photosystem II
• Photosystem: a cluster of chlorophyll and proteins
found in the thylakoids.
• Light is absorbed by photosystem II which creates high
energy electrons.
• A water molecule is split to provide more electrons and
hydrogen ions and oxygen is released.
Step 2: Electron Transport Chain
• The electrons from photosysem II move to the electron
transport chain.
• Electrons move from molecule to molecule to pump H+
ions from the stroma into the thylakoid space.
• What type of transport is used to move the H+ ions?
Explain