DEFINITIONS OF COMMON BIOLOGY CONCEPTS

LIST OF DEFINITIONS

Antibiotic Resistance: a type of drug resistance where a microorganism or cell is able to survive exposure to an antibiotic.

Cell: the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing and is often called the building block of life.

Cell Culture: the complex process by which cells are grown under controlled conditions.

Cell Type: a distinct morphological or functional form of cell. Several hundred distinct cell types exist within the human body. Examples include nerve cells, gland cells, liver cells and muscle cells.

Cell Membrane: 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. Its basic function is to protect the cell from outside forces. It consists of the lipid bilayer with embedded proteins.

Chromosome: an organized structure of DNA and histones found in the nucleus of cells.

Clone: a group of identical cells that share a common ancestry; meaning they are derived from the same mother cell.

Contract Research Organization (CRO): a service organization that provides support to the pharmaceutical and biotechnology industries in the form of research services outsourced on a contract basis. A CRO can provide such services as biopharmaceutical development, preclinical research, clinical research and clinical trials management.

Deoxyribonucleic Acid (DNA): a nucleic acid containing the genetic instructions used in the development and functioning of all known living organisms. The DNA segments carrying this genetic information are called genes.

Enzyme: made by DNA, enzymes are long, complex molecules that have the function of speeding up chemical reactions inside the cell. Very specific enzymes carry out specific actions in specific amounts, which are essential to regulating normal life functions of the cell. *

Mitosis: the division of the mother cell into two daughter cells, genetically identical to each other and to their parent cell.

Nucleus: referred to as the “control center” of the cell because its function is to control the activities of the cell by regulating gene expression. The nucleus contains most of the cell’s genetic material, organized as multiple long, linear DNA molecules, which form chromosomes. *

Petri Dish: a shallow glass or plastic cylindrical lidded dish that biologists use to culture cells.

Plasmid: a DNA molecule that is separate from and can replicate independently of the chromosomal DNA.

Protein: a long complex molecule made within cells by translation from a RNA molecule. Enzymes are one example of a type of protein, but they also have structural functions. Proteins are used in virtually every process within the cell and are one of three essential macromolecules, along with DNA and RNA, for all known life. *

Ribonucleic Acid (RNA): one of the three major macromolecules (along with DNA and proteins) that are essential for all known forms of life. Like DNA, RNA is made up of a long chain of components called nucleotides. The sequence of nucleotides allows RNA to encode genetic information. All cellular organisms use messenger RNA (mRNA) to carry the genetic information that directs the synthesis of proteins.

Stable Transfection: the generation of a stable cell line of successfully and fully transfected genes. It differs from transient transfection in that it is a permanent state where the desired transfected genes have fully integrated themselves into the host cell’s chromosomal DNA. *

Transfection: the process of deliberately introducing genetic material into cells.

Transient Transfection: the generation of a cell line where a desired transfected gene is expressed. It differs from stable transfection in that it is only a temporary state in which desired transfected genes exist in the cytoplasm or even the nucleus, but eventually are degraded.

Transfection Reagent: something that is used during the generation of stable cell lines. A transfection reagent is added to aid the desired genetic material in accessing and incorporating itself into the cell’s DNA. *

Source for most definitions from Wikipedia as of Feb. 2012.
*Definition provided by StableTransfection.com

STABLE TRANSFECTION | TRANSIENT TRANSFECTION | DEFINITIONS