The amazing part of antibody production is the fact that the instructions on how to make so many of them are found in the DNA. DNA is divided up into segments, called genes, which have the instructions on how to make proteins.  If there are only about 23,000 genes in human DNA, how do our cells make so many different types of antibodies? The number of antibodies exceeds the coding capacity of DNA tremendously.

This brings up a whole list of events that leads to antibiotic diversity, including the recombination of gene segments in the production of the protein. Multiple gene segments will recombine in the blood cells to form the heavy and light chain in the antibody. Just to give you an idea about how diverse they can be, the heavy chain itself has almost 11,000 different combinations that can result from the recombination of all of the gene segments. After a variety of antibodies are produced, random somatic mutations will occur which lead one specific antibody being able to bind to the antigen that is present.

To learn more about how cells read the instructions in DNA to make proteins, see http://www.dnai.org/a/index.html.

Protein is a broad category that includes enzymes and hormones. When you eat an apple, your body produces enzymes to break down that apple and build new products for your body. If you have a lot of glucose (a type of sugar) in your blood, the cells in your pancreas will read the gene for insulin and produce the protein. Even the tight skin of youth relates to proteins. The elasticity of your skin depends, in part, on the production of the protein collagen in your skin cells. As humans get older we produce less collagen, which is one of the reasons our skin becomes less taut.

If an organism has a change, or mutation, in their DNA what can this mean? If the mutation happens in a region of DNA that does not code for anything then the mutation may go unnoticed. If, however, the mutation happens in a coding region of a gene, then protein production may be affected. In some cases, the change in DNA can cause a protein to be produced that will have no function or even be destroyed by the cell. In contrast, the protein may be produced in larger amounts or at different times.

Another possibility is that the altered protein may be just slightly different. This new protein may be able to even carry out the same job of the original one. Also, the new protein may offer a new function or provide a new trait for the organism. All of these possibilities offer variety in life.

Although there is often a negative association with mutations because of their role in causing genetic disease, life would not exist without them.