Question

In Mitochondria what do the following parts do:

-Granules
-Cristae
-DNA
-Inner membrane
-ATP synthetic particles
-Matrix
-Outermembrane
-Inner membranespace

I would like this to be easy to understand. Not too in depth. Thank you!

Answer 1

Some theories have it that mitochondria were initially free living organisms which, over the eons, got taken up and incorporated into cells where they now perform very specialized functions.

The outer membrane is similar to the plasma membrane of the cell, in lipid and protein composition, and like the plasma membrane is permeable to small ions but not to proteins.

Inside the inner membrane is the inter-membrane space, not inner membrane as you have it.

The inner membrane is more interesting. If the endosymbiotic theory is right, this was the outer membrane of the little cell which got incorporated into the eukaryotic cell. Its most intrinsic function is to maintain the electrochemical gradient between the inter-membrane space and the matrix inside the mitochondria which drives electron transport, but it has a few other properties associated with that function as well: home to the protein machinery involved in electron transport and ATP synthase.

Cristae are infoldings of the inner membrane - infoldings increase the surface area available for use in electron transport, which means mitochondria with more cristae can make more ATP per unit time.

The matrix is just what's inside the inner membrane, a lot of calcium ions; the mitochondrial DNA is probably left over from when the mitochondria were free living prokaryotes and contains some specific genes which the mitochondria need but which the rest of the cell doesn't, really.

Really though, you'd find better info on the Wiki page or in any intro biology book like the ones by Campbell or Lodish...