Mitochondria are the cells' power sources. They are distinct organelles with two membranes. Usually they are rod-shaped, however they can be round. The outer membrane limits the organelle. The inner membrane is thrown into folds or shelves that project inward. These are called "cristae mitochondriales". This electron micrograph taken from Fawcett, A Textbook of Histology, Chapman and Hall, 12th edition, 1994, shows the organization of the two membranes.
Use the study guide below to navigate through this handout. The links lead to answers to the questions, in case you can't remember. If you can answer these questions, you will do well on the exam.
Test yourself!! How much do you already know about mitochondria?
 | Describe the basic substructure of mitochondria. |
| How are mitochondria organized to be powerhouses? Where are each of the major systems? |
| Mitochondrial Geography: Trace the structural pathway leading from the products of glycolysis to the Kreb's cycle and the electron transport chain. What are the final products? Where does each event occur in the mitochondrion? |
| What is the significance of an increase in the number of cristae in a mitochondrion? |
| What is the structure and function of the inner membrane and elementary particles? |
| How do mitochondria replicate? |
| Are mitochondria completely dependent on nuclear DNA and ribosomes? |
| What happens to old, worn-out mitochondria? |
| If the inner membrane is so impermeable, how do proteins enter? |
| How does mitochondria export ATP, cytochrome C or apoptosis inducing factor? |
| How are mitochondria involved in steroid biosynthesis? |
| How are mitochondria involved in apoptosis? |
