Medical Physiology - Genetic Regulation of Cell Function, Protein Synthesis, and Cell Division

Medical Physiology - Genetic Regulation of Cell Function, Protein Synthesis, and Cell Division
Cell Nucleus Genes Regulate Synthesis of Proteins The genes regulate the cell's production of proteins, which in turn regulates cell activity. As fundamental constituents of the cell's physical structures and as enzymes that catalyze the cell's operations, proteins are essential for nearly every function of the cell. Every gene regulates the formation of ribonucleic acid (RNA) and is a double-stranded, helical molecule of deoxyribonucleic acid (DNA). The RNA then circulates throughout the cells to regulate the production of a certain protein. Gene expression is the term used to describe the complete process,, from transcription of the genetic code in the nucleus to translation of the RNA code and the creation of proteins in the cell cytoplasm.

Each cell contains over 30,000 genes, which allows for the formation of a vast array of distinct cellular proteins. Two strands of DNA are formed by the loose binding of nucleotides. Long, double-stranded, helical molecules of DNA, which are made up of three fundamental building blocks—phosphoric acid, deoxyribose, a sugar, and four nitrogenous bases—two purines (adenine and guanine) and two pyrimidines (thymine and cytosine)—are where genes are joined end-on-end. One phosphoric acid molecule, one deoxyribose molecule, and one of the four bases combine to form a nucleotide, which is the initial step in the creation of DNA. As a result, each of the four bases can produce one of the four nucleotides. Two strands of DNA are created by joining many nucleotides, and these strands are only loosely connected to one another. Phosphoric acid and deoxyribose molecules alternate to form the backbone of every DNA strand. The purine and pyrimidine bases are joined to the side of the deoxyribose molecules, and the two DNA strands are held together by loose links between their purine and pyrimidine bases.

While guanine always forms a link with cytosine, the purine base adenine of one strand always forms a bond with the pyrimidine base thymine of the other strand. Triplets of bases make up the genetic code. A code word is any collection of three consecutive nucleotides in the DNA strand; these code words regulate the the protein's amino acid sequence that will be created in the cytoplasm. For instance, a code word may consist of adenine, thymine, and gua-nine, whereas the subsequent code word may consist of cytosine, guanine, and thymine. Due to the differences in their basis, these two code phrases have completely distinct meanings. The genetic code is the string of consecutive code words that make up the DNA strand.