Mitochondrion

source of image: www.britannica.com

I thought a good way to start the New Year right is to talk about cell energy and the mitochondrion.

The mitochondrion is an organelle that is involved in energy production. It is a rather complex organelle, it will probably take a few posts to completely its story.

Anyway, just to get started, let’s first talk about its structure today.

A mitochondrion (plural, mitochondria) is usually rod-shaped but this shape can change at anytime under varying conditions. It has a double membrane, the outer one being smooth and the inner one being thrown into folds called cristae (sing. crista). These folds increase the area for enzymes embedded in it and the more active a cell is, the more folds there are. Thus, a heart muscle cell for example has more cristae in its mitochondrion compared with a cartilage cell's mitochondrion.

There is a narrow space between the outer and inner membranes of the mitochondrion. This space is called the intermembrane space. Another space is found in the middle of the mitochondrion and this is called the matrix space or simply the matrix. Contents in both spaces differ.

The contents of the intermembrane space are somewhat similar to that of the cytosol whereas the matrix space contains many enzymes involved in the Kreb’s cycle process. Ribosomes as well as a circular DNA and tRNA are also found in the matrix.