Human Cell Functions

A) Mitochondrion- Mitochondria is the powerhouse of the cell. They are complex organelles that convert energy from the food you eat into a form that the cell can use. They have their own genetic material, dna and ribosomes, separate from the DNA in the nucleus, and can make copies of themselves. The mitochondria also produces over 90% of ATP (adenosine triphosphate) in the cell. Mitochondria can also grow larger or combine with another mitochondria if it needs to. The mitochondria is made up of three main parts. These are the outer membrane, the inner membrane and the matrix. The outer membrane covers the organelle and hold everything in. The inner membrane holds over and creates a layered structure called cristae and the fluid contained the mitochondria is called the matrix.

B) Ribosome- ribosomes are organelles that process the cell's genetic directions to create proteins. They can float around the cytoplasm or be connected to the endoplasmic reticulum. They are composed of RNA and proteins. The ribosomes that are attached to the endoplasmic reticulum are called the bound ribosomes. Ribosomes are made up of two different subunits- the large subunit and the small subunit. Both of these are composed of RNA and protein. These usually exist separately in the cytoplasm until a the small subunit recognizes a specific sequence in a RNA message. The large subunit then forms the complete ribosome.

C) Cytoplasm- Within the cell, cytoplasm is made up of a jelly like fluid as well as other structures that surround the nucleus. The cytoplasms hold different parts of the organelles together. It provides suspension solution for the organelles and the cytoskeleton gives shape, due to which in and out movement of the membrane is made possible. Organelles like the mitochondria are incapable of breaking down glucose which is essential for providing energy. The cytoplasm and the enzymes within it break down the macromolecules into small portions to facilitate energy production for the mitochondria’s of all the cells.

D) Smooth endoplasmic reticulum- The smooth endoplasmic reticulum is associated with the production and metabolism of fats and steroid hormones. The reason that it is smooth is because it does not have ribosomes surrounding it, therefore associating it with smooth slippery fats. The smooth ER is found evenly distributed throughout the cytoplasm. Its main job is the making of lipids and in some cases the metabolism of them. For example, in liver cells the smooth ER enables glycogen that is stored in fragments on the external surface of the smooth ER, to be broken down into glucose.

E) Rough endoplasmic reticulum- The rough endoplasmic reticulum is involved in some protein production, protein folding, quality control and despatch. It is called rough due to ribosomes that are studded all over it. It is an extensive organelle composed of a greatly convoluted but flattish sealed