The Secrets of the Human cell

The Secrets of the Human cell.

           Every human being begins life as a single cell, a fertilized egg, by the time reachers adulthood his body consists of 100 trillion cells. The cell is a fundamental component of all living thing. As cells deteriorate, people age. As calls malfunction, people get sick. If cells were better understood, people might live longer and stay healthier. And thanks to a recent series of extraordinary breakthroughs, scientists are beginning to learn more about them. One of the molecular biologists says that we are on the verge of a revolution in the understanding of cells.

           Scientists discovered three centuries age that living things contain cells, but only in the last three decades have they begun to piece together the puzzle of how cells operate. They know a few fundamental things: every single adult cell (except ova and sperm) contains the same set genes as the original cell. Still cells come in the shapes, sixes and functions slim nerve cells: more than three feet long and about 1 forty-thousandth of an inch wide: transmit impulses between the limbs and the brain: red blood cells 3 ten-thousandth of an inch in a diameter carry life-giving oxygen around the body. But researchers remain baffled by the chemical mechanism that enables particular genes in different cells to switch themselves on and off perform differently in varying circumstances.

          Each of those trillion cells functions like a walled city. Rower plants generate the cells functions like energy. Factories produce proteins, vital units of chemical commerce. Complex transportation systems guide specific chemicals point to point within the cell and beyond. Sentries at the barricades control the export and import markets, and monitor the outside world for signs of danger. Disciplined biological armies stand nearly to grapple with invaders. A centralized genetic government maintains order.

          Toxic garbage. Cells occasionally go wrong. Recycling systems can break down, overloading the cells with their own toxic garbage the result fatal Tay-Sachs disease, or some similarly horrendous genetic ailment. Confused by erroneous information, internal factories can add many chemicals to an already abundant supple that they eventually flood the whole body: the resulting accumulations of cholesterol lead directly to cardiovascular disease. A breakdown in communications between the nuclei of cells and their outer borders can produce the unrestricted growth that causes cancer. Evan if they operate smoothly, normal cells eventual succumb to old age-the process of biological decay that alters the cells and kills organism of which they for the basic units. Biologists think they eventually can treat many of defects by turning the intricate machinery in each cell to the patient's advantage. For instance, chemicals find their way to appropriate places in the cells through what scientists call "zip=code". To overcome genetic diseases that leave cells bereft of vital chemicals, biologists might manufacture the chemicals in a test tube, attach the proper chemical address to them, and inject them into the dody-knowing that they will end up where they will do the most good. Similarly, to treat certain forms of cancer, scientists are learning to manufacture digestive sacs within the cells known as lysosomes. A cell ordinarily will reiect many poisons. But if a drug-intended to poison a cancerous cell-is disguised with food, it might be accepted by the cell released by the lysosomes.