The cell is the basic structure of the body. The human body is built of billions and trillions of cells. Each cell contains the hereditary material and can make copies of themselves by reproducing and multiplying. After a specific life span the old cells die off. Parts of the cell are called organelles. Human cells contain the following major parts:
• Nucleus – This is central part of the cell that carries the blue print for the cell functioning and tells the cell when to grow, reproduce and die. It also houses DNA (deoxyribonucleic acid).
• Mitochondria – These are the powerhouses of the cell and produce energy for the various activities of the cell.
• Cytoplasm – This is a jelly like fluid within the cell in which the other organelles float.
• Endoplasmic reticulum (ER) – This helps in processing the molecules (e.g. proteins) created by the cell.
• Ribosomes – These lie over the ER and process the genetic instructions or the blueprints within the DNA and create new proteins. These can also float freely in the cytoplasm.
• Lysosomes and peroxisomes – These help in digesting foreign bacteria that invade the cell, rid the cell of toxic substances
• Cell membrane – This is the outer lining of the cell.