We start with the cell, because so much of what happens to us when we get sick, and how we get healthy again, can be explained by what happens on a cellular level. The cell is extremely complex and I will only touch on the basics in these posts, but at least we can have a rudimentary understanding.
We have discussed cell membranes (May 23), as well as cell organelles (May 30). On June 6, we discussed the cellular transport mechanisms and on June 13 the cell nucleus. We discussed cell division on June 20 and today we end the series on the cell with a very short look at protein synthesis.
Although cells synthesize many chemicals to maintain homeostasis, they are mainly devoted to synthesizing large numbers of proteins. Proteins are used as enzymes and as structural materials in the cells. Many proteins are retained in the cell for intracellular use. Some proteins are used to assemble cellular structures such as the plasma membrane, the cytoskeleton and other organelles. There are many specialized human proteins that are exported and function in cellular activities. For example, protein makes up the hormone insulin, the ligaments and tendons of joints, the hair, skin, and nails of the body.The instructions for making proteins are found mainly in the DNA in the nucleus. For protein synthesis to occur, there are several essential materials that must be present: a supply of the 20 different amino acids, a series of enzymes, DNA, and ribonucleic acid (RNA). The information encoded in a region of DNA is first copied to produce a specific molecule of RNA. Then the information contained in the RNA is translated into a corresponding sequence of amino acids that forms the protein molecule. The code for a single amino acid consists of three bases in the DNA molecule: this triplet of bases may be called a codon. The genetic code is the set of rules that regulate the base triplet sequence of DNA to the corresponding codons of RNA and the amino acids they specify. If there is a mistake in the DNA, that is, incorrect bases or triplets of bases, this mistake will be copied. The result is the formation of a malfunctioning or non-functioning protein. This is called a genetic or hereditary disease.How does this affect you?
In tumor growth, protein synthesis is altered. One study found that the increased protein synthesis that occurs when a tumor is present is similar to that which occurs with inflammation. This knowledge can lead to better cancer therapies as well as to a better understanding of tumors.
1. Thank you Riana for your six-part essay on cell form and function. It was quite nice. Any number of oncologists' training and practice does not include studying and understanding the cancer cell and its relationship to the rest of the body's cellular mechanics and communication. Cellular biology is a very complex and fascinating body of knowledge which a number of private clinical scientists (the Geeks, MD/PhD's)appreciate and understand. They are constantly looking for ways to reverse that cell physiology and in a non-toxic way as possible. Continued development of better cancer drugs is driven by increased understanding of cancer cell biology. Perhaps if some oncologists did rotations like medical students do, they would develop more of an understanding and appreciation of what it is they are doing.
Posted at 7:53PM on Jun 27th 2007 by Gregory D. Pawelski