Anti aging guide

What sets and stop the biological clock?



What sets the biological clock?

It is well known to the life insurance industry that the genes exert a major influence on aging and longevity. He who would live to a ripe old age would do well to choose his parents wisely, and different animal species, as we shall see, age at vastly different rates. Down’s syndrome is a genetic disorder characterized by the presence of an extra chromosome number 21, and people with this condition show some signs of accelerated aging, including the deposition in the brain of amyloid composed of the same protein fragment as is found in the age-related dementia of Alzheimer’s disease. The gene encoding the amyloid protein is located on chromosome 21-in very close proximity to the gene which transmits the rare familial form of Alzheimer’s disease.

What stops the biological clock?

Each animal cell contains over 200 million protein molecules, each of which has been assembled from amino acids according to a precise pattern specified by DNA (deoxyribonucleic acid), the material which stores genetic information, and acts as a programme or blueprint. The template for protein synthesis is transmitted from the DNA in the nucleus to the cytoplasm in the form of smaller, readily transported messenger molecules called RNA (ribonucleic acid) which link with protein to form complexes called ribosomes where the protein molecules are assembled. The DNA and the ribosomes have to be intact in order that protein synthesis can proceed and the cell continue to undergo division.

Should any errors develop in the transcription of information from DNA to RNA or its onward relay to the protein molecule on the assembly line, a strain of abnormal and defective protein (whether structural or enzyme) would emerge. Such errors probably do not arise simply as a result of advancing age, but they can be caused by a number of environmental factors, including heat, cold, ultraviolet light, irradiation, free oxygen (`super oxide’) radicals, and even glucose. An accumulation of environmentally mediated errors over the years could result in the production of more and more lines of defective protein and malfunctioning or non-replicating cells. The mechanisms for detecting and repairing or eliminating these errors may become less efficient as the organism ages.

During cell division, alterations occasionally take place in the structure of a chromosome which may be fairly gross or may affect a single gene locus or a few neighboring gene loci. These alterations, called mutations, occur particularly as a result of irradiation and other harmful stimuli, but can also occur on a spontaneous basis. Mutations fundamentally affect the DNA and thus the encoded information, and this is one of the mechanisms whereby environmental factors influence the integrity of the cell, the tissue, and thus the organism.

Posted by Carol Hudgens - April 19, 2012 at 4:40 pm