Essay by karrenkazaCollege, Undergraduate November 2014

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Human physiology Cells Karren Dutton

Human physiology Cells Karren Dutton

Although no one-cell type is the same, cells do have the same basic parts and functions that are common to all cells. A generalized cell will have three main regions - a nucleus, cytoplasm and plasma membrane.

Cells contain multiple organelles, unlike bacteria, which is a single organelle. Cells differ in size, numbers and their function. Organelles are responsible for the complex processes that aid the human body to work at its best, accomplishing tasks, which may not be possible without the help of other organelles.

A cell is surrounded by plasma membrane. This acts as barrier between the inside of the cell and the outside. Within this is the nucleus, the control center of the cell, which commands the rest of the cell. Nucleus is only found in eukaryotic cells, and although most cells within the body are eukaryotic there are a few exception.

The nucleus is usually to the center of the cell and surrounded by semi-fluid cytoplasm (where most cellular activity occurs) by means of a nuclear envelope, a double membrane-containing small nuclear pores. The outer membrane is connected to the outer rough endoplasmic reticulum (ER). The rough ER synthesizes proteins and other components with the help of ribosomes it controls the substances between the cytoplasm and nucleus, e.g. proteins.

In addition the smooth endoplasmic reticulum (ER) that extends outwards from the rough ER synthesizes fats, and unlike the rough ER It lacks ribosomes on its outer surface, which is the reason for its smoother appearance, it is also more tube-shaped than the rough ER.

Ribosomes, located within the nucleus are attached to the nucleolus, which contains both RNA and DNA, which play a significant role in protein synthesis. Enzymes are made of proteins, which are...