• Chapter 7.

The Cell: Chloroplasts

Overview

Chloroplasts are organelles that convert energy to forms that cells can use for work

chloroplasts:from sunlight to ATP & carbohydrates

ATP = active energy carbohydrates = stored energy

Chloroplasts

Chloroplasts are plant organelles chloroplasts

store chlorophyll & function in photosynthesis

in leaves, other green structures of plants & in eukaryotic algae

Chloroplasts

Function photosynthesis

generate ATP & synthesize sugars transform solar energy into chemical energy produce sugars and oxygen from CO2 & H2O

Structure of a Chloroplast Structure

2 membranesouter membrane inner membrane

Structures of a Chloroplast

• Thylakoid- system of membrane that is arranged in flattened sacs

• Light reactions take place in the Thylakoids.

• Chemiosmosistakes place across the membrane of a Thylakoid.

Structures of a Chloroplast

• Granum (grana is plural) – stack of connected and layered thylakoids

Structures of a chloroplast

• Stroma- solution that surrounds the grana

The Calvin Cycle (light- independent reactions) takes place in the stroma.

Why are chloroplasts green??• Chloroplasts contain a green pigment called

chlorophyll. This is what makes plants green

• Chlorophyll has a green pigment • Pigment = a substance which produces a

characteristic color as a result of the color (of light) being reflected because of its wavelength