Energy-Related Organelles

Two types of membranous organelles that specialize in energy conversion are the chloroplasts and mitochondria.


Chloroplasts use solar energy to make carbohydrates by using photosynthesis.


Mitochondria break down carbohydrates to produce adenosine triphosphate (ATP). ATP supplies the energy the cell needs to do work.



Chloroplasts are found in plants and other photosynthetic organisms.


The large inner space is the stroma and is filled with fluid. The fluid contains enzymes that are used for photosynthesis.

Thylakoids are disk-like sacs that contain the green pigments that absorb light energy.

 Thylakoids are organized into stacks. Each stack of thylakoids is called a granum.






Mitochondria are surrounded by a double membrane.


The folds of the inner membrane are called cristae. ATP is produced on the cristae and the folds help to increase surface area so that more ATP can be made.


The inner membrane encloses the matrix- a fluid filled compartment



Mitochondria are often called the cell  "power-house" because they produce most of the ATP.


The breakdown of food molecules in the presence of oxygen to produce ATP is called cellular respiration.


 Toggle open/close quiz question

Which of the following is true?
    a.Chloroplasts make sugars and mitochondria break sugars down.
    b.Chloroplasts burn sugar.
    c.Mitochondria absorb light.
    d.Chloroplasts make most of the cell's ATP.