Bio Thingy - Mitochondria

Part C - Mitochondria

The mitochondria is one of the most important organelles found in the cell, because many of the metabolic processes that are required for normal body function occur here. Depending on the type of cell and where it is found, there can be up to 1000 mitochondria in a single cell. Cells that require the most energy contain the most mitochondria.

The purpose of the mitochondria is to make an energy source in the form of Adenosine Triphosphate (ATP) for use in the body, from the food that the organism takes in. In plants, ATP is also produced from light by the reactions in photosynthesis. Glycolysis is the first stage of aerobic respiration and is the breaking down of glucose that occurs within the cytoplasm. The products of this reaction are used in the Krebs or TCA cycle, which occurs in the matrix of the mitochondria, and then by the Electron Transport Chain which occurs across the inner membrane of the mitochondria. This reaction creates ATP by the ATP Synthase that is also on the inner membrane of the mitochondria.

The mitochondria contains two membranes called the inner and outer membrane, which are made up of a phospholipid bilayer and proteins. A phospholipid bilayer is a thin membrane made up of two layers that provide a continuous barrier around the cell to protect it and also to control the concentration of solutes in and out of the organelle.

The outer membrane surrounds the whole organelle and is permeable to many ions and molecules.

The inner membrane is impermeable to most ions and molecules, so contains many integral protein channels that cross the membrane and allow the transport of solutes into and out of the matrix. An example of this is the aquaporin channels that allows for the diffusion of water.

The inner membrane needs to remain intact because strict control of the metabolic enzymes is important to allow the processes to occur. If the outer membranes are disrupted, the solutes in the intermembrane space...