The mitochondrion is an organelle found in eukaryotic cells (Tortora 1992). A mitochondrion can occur in different shapes inside one cell. Mitochondrion can be long, like a rod, and filamentous or compact, like a sphere, and granulelike (Wolfe 1993). There are approximately 1700 mitochondria in an average cell. Mitochondrion range from .5 to .1 mm in diameter, which is about the size of a bacterium (Alberts 1983). Mitochondrion contain ribosomes, have their own DNA, can replicate and transcribe their DNA, synthesize enzymes into ATP, and reproduce by growing and dividing (Tortora 1992).
             Mitochondria are double membrane bound; meaning it has both an outer and inner membrane. The outer membrane is a smooth, continuous covering (Tortora 1992) that appears blue in figure one, below. The outer membrane protects the organelle and is permeable to molecules that are 10,000 Daltons or less (Alberts 1983). Separating the outer and inner membranes is an area called the intermembrane space. The inner membrane is folded many times. These folds, know as cristae, give the inner membrane a considerably larger surface area creating a larger space for reactions to occur (Tortora 1992). The cristae are very important because this is the site where ATP synthesis occurs (Encarta 2001). The center of a mitochondrion is filled with a semifluid substance called the matrix (Tortora 1992). The matrix contains the enzymes that are
             necessary for aerobic respiration (Encarta 2001).
             Mitochondria are known as the "powerhouse" of the cell. They are given this name because they convert nutrients into ATP, which gives the cell energy to function. This process is known as aerobic respiration. During aerobic respiration, the Krebs cycle occurs and pyruvic acid reacts with water, producing carbon dioxide and ten hydrogen atoms. These hydrogen atoms are transported to the cristae where they are donated to the electron trans...