Structure of a Chloroplast

What are chloroplasts?

Flattened organelles found in plant cells

Structure of a chloroplast

• Chloroplast envelope - double membrane

• Thylakoid membranes arranged into grana that are linked by lamellae

• Photosystems

• Stroma

What is the function of the chloroplast envelope?

Keeps the reactants for photosynthesis close to their reaction sites

How are the thylakoid membranes specialised for their function?

They are have large surface area

It contains chlorophyll (photosynthetic pigment)

It can maximise the light energy absorbed

Contain lots of ATP synthase for ATP production

What are thylakoids?

Fluid filled sacs

What are grana?

A stack of thylakoid membranes

What are lamellae?

Pieces of thylakoid membrane that link grana together

What are photosystems?

Proteins that have chlorophyll pigment

Found in the membrane of thylakoids

What is the use of chlorophyll?

• Photosynthetic pigments that absorb light energy

• Found in photosystems

What are the two photosystems called and what wavelength of energy can they absorb the best?

• PSII - 680nm

• PSI - 700nm

What is the Stroma and how is it adapted for its function?

• gel like substance surrounding the thylakoids

• Contains enzymes, sugars, organic acids - for light independent reaction

• Contains oil droplets which store non carbohydrate organic material