The mitochondria is an organelle often referred to as “the powerhouse of the cell” is located in all eukaryotic cells. These cells can be found in organisms such as animals, fungi, plants, and protists (Algae). Mitochondrion can range from 100 – 1000 per cell depending on the function and type of cell. The main function of this organelle to produce energy for the cells biochemical reactions through a process called oxidative phosphorylation. To truly understand this organelle you must break it down its structure and understand the roles each of them play.

Structure

Outer-membrane

The outer-membrane act as a barrier. It is made out of a phospholipid bilayer. It is highly permeable, meaning it allows many things to pass through such as proteins, ions, ATP, ADP, and most nutrients. It is also very important to keep the the structure of the mitochondria.

Inner-membrane

This also is a phospholipid bilayer however it is not as permeable as the outer membrane. It is very selective on which proteins are allowed to pass. Such as uncharged oxygen, carbon dioxide and water can pass freely while molecules such as pyruvate, ADP, ATP, and certain metabolites needs a transport protein which happens in the inter-membrane space.

Inter-membrane Space

Between the inner and outer membrane resides the inter-membrane space. It is highly concentrate with proton ions. This area is plays a role in protein transport, by importing and sorting other proteins passing through the inner-membrane. This layer is also crucial for ATP production by maintaining an ion gradient.

Cristae

The folds on the inter-membrane increase the surface area and efficiency of ATP production. It is a continuation of the inter-membrane for metabolic reactions.

Matrix

Is a gel-like liquid, which consists of mitochondrial DNA and ribosomes. It also increase the surface area for efficient ATP production.

Mitochondrial DNA (mtDNA)

This DNA is inherited by the mother. It allows the mitochondria to convert food into energy which is essential for ATP production. It also codes transfer RNA (tRNA) and ribosomal RNA (rRNA) which then assembles amino acids into proteins causing protein synthesis.

Ribosomes

The main function of ribosomes is to synthesize protein. It will receive information about the type of protein that is needed from a messenger RNA (mRNA). It then is translated it into a chain of amino acids. The amino acids then forms a long chain which then folds to form a protein.

Function

Oxidative phosphorylation (ATP Production)

Oxidative phosphorylation is a process in which the mitochondria produces ATP. This occurs when our bodies take in broken down food molecules such as glucose and other nutrients. It then goes through a process called the TCA cycle which then create electrons that are transferred through an electron transport chain on the inner membrane. This then causes protons to pump across the membrane creating a proton gradient. In return causes the movement of protons back through ATP synthase, which turns ADP (Adenosine diphosphate) into ATP (adenosine triphosphate) which is a process called ATP synthesis. This allows the mitochondria to deliver energy to other areas of the cell allowing to fulfill it functions making it the powerhouse of the cell.