MITOCHONDRIA:

Size & Shape:

• Long Oval Shaped organelle
• 1 mm to 4 mm in length and 0.2 mm to 1.0 mm in diameter.
  

Location:

• Within the cytoplasm of the cell
• Makes up 15-20% of cell’s total volume.
  

Function:

The mitochondria are responsible for energy transduction within the cell. The mitochondria structure is vital for this energy production. The organelle consists of two membranes: both an inner and an outer membrane. The outer membrane acts as a selectively permeable barrier for the organelle, where the inner membrane encloses the matrix of the mitochondria. The inner membrane has many invaginations, known as cristae. The energy producing reactions of the mitochondria take place on these cristae. During carbohydrate metabolism within a cell, the products of glycolysis enter the mitochondria to go through the TCA cycle. This cycle is responsible for producing high-energy electron carriers. These electron carriers are ultimately transported across an electron-transport chain, which is situated across the inner mitochondria membrane. In being transported along the chain, the electron carriers provide the cell with a great deal of energy.

In addition to being the primary organelle involved in cellular metabolism, the mitochondria also controls the level of water and other materials within the cell. This organelle works to recycle and decompose proteins, fats, and carbohydrates.

The mitochondria are one of the most important organelles within the cell. Through a process known as endosymbiosis, the earliest anaerobic cells developed a symbiotic relationship to a mitochondrion. The uptake of the mitochondrion into the anaerobic cell led to the evolution of an aerobic cell, or one that utilizes oxygen. Because of the presence of the mitochondria, cells were given extra energy, from which they could form more complex components. Eventually, the development of specialized cells, known as eukaryotic cells, led to the origin of organisms on Earth.

Related Organelles: Chloroplast, Cytoplasm.