4.7.1 Study Notes Energy Organelles

A. Chloroplasts 

• are membranous organelles (a type of plastid) that serve as the site of photosynthesis

  • bound by a double membrane organized into flattened disc-like sacs called thylakoids

    • a stack of thylakoids is a granum.

• Photosynthesis: 

  • solar energy + carbon dioxide + water → carbohydrate + oxygen

  • conducted only in plants, algae, and certain bacteria

• contain:

  • chlorophyll

  • other pigments 

  • capture solar energy

  • enzymes which synthesize carbohydrates

• contain their own DNA and ribosomes

  • supporting the endosymbiotic hypothesis

B. Other types of plastids

• differ in color, form, and function

• include: 

  • chromoplasts 

  • leucoplasts

C. Mitochondria 

• organelle surrounded by a double membrane:

  • the inner membrane surrounds the matrix 

  • convoluted to form cristae.

• smaller than chloroplasts

• vary their shape.

• also can be fixed in one location or form long, moving chains

• contain ribosomes and their own DNA

  • supporting the endosymbiotic hypothesis

• the matrix 

  • concentrated with enzymes that break down carbohydrates

• the cristae

  • ATP production

• disease of the mitochondria

  • more than forty different disease have been identified