Cells: Protein and Endoplasmic Reticulum Essay example

Submitted By lerma15
Words: 536
Pages: 3

Victoria Z-Lerma
Period-4.
Biology
5/6/13
Cells

The nucleus of cells is a membrane enclosed organelle found in eukaryotic cells. It contains most of the cells genetic information. The function of the nucleus is to maintain the integrity of the genes and to control the activities of the cell, therefore the nucleus is the control center of the entire cell. The structure of the nucleus is made up of a double membrane that encloses the entire organelle and isolates its contents from the cellular cytoplasm. Mitochondrion is a membrane-enclosed organelle found in most eukaryotic cells. These organelles range from 0.5 to 1.0 micrometer in diameter. Mitochondria are sometimes described as “cellular power plants” because they generate most of the cells supply of ATP, used as a source of chemical energy. In addition to supplying cellular energy, mitochondria are involved in other tasks such as signaling, cellular differentiation, cell death, as well as the control of the cell cycle and cell growth. Mitochondria have been implicated in several human diseases. The number of mitochondria in a cell varies widely by organism and tissue type. Many cells have only a single mitochondrion and others may contain several thousand mitochondria. The endoplasmic reticulum is an organelle of cells in eukaryotic organisms that forms an interconnected network of membrane vesicles. The structure of the endoplasmic reticulum is classified in two types, which are rough ER and smooth ER. The rough ER is studded with ribosomes. The rough endoplasmic reticulum is predominantly found in hepatocytes where protein synthesis occurs actively. The smooth endoplasmic reticulum is a smooth network without the ribosomes. The smooth endoplasmic reticulum is abundantly found in mammalian liver and gonad cells. The cell membrane is a biological membrane that separates the interior of all cells from the outside environment. The cell membrane is selectively permeable to ions and organic molecules and controls the movement of substances in and out of cells. The basic function of the cell membrane is to protect the cell from its surroundings. It consists of the lipid bilayer with…