Lab Sheet - Central Dogma of Molecular Biology
Introduction
A gene is a unit of heredity. A gene is also the segment of deoxyribonucleic acid (DNA) that codes for a specific protein. It is the roughly 25,000 genes of the human genome that make the entire human organism. This lab illustrates the processes that take us from gene to protein - in other words, the steps that take us from four nucleic acids to the human organism.
Objective
* Describe the DNA structure and the Central Dogma of Molecular Biology.
Background
Genes and DNA
Genes code for proteins. It is the specific action or function of these proteins that determines cellular shape and cellular function. The processes that take us from the sequence of nucleotides to protein are collectively called the Central Dogma of Molecular Biology.
The process begins with a sequence of nucleotides. There are four nucleotides in DNA- adenine, guanine, cytosine, and thymine abbreviated A, G, C, and T, respectively. The structure of DNA is a double helix- a winding staircase structure where the rungs of the staircase are made up of the nucleotides; the railing, or backbone, is made up of sugar- in the case of DNA, the backbone is made up of the sugar, deoxyribose. The nucleotides pair up as complementary pairs to make up the “rungs”- A always pairs with T, C always pairs with G; this is called the Law of Complementary Base Pairs. The complementary pairs are held together by hydrogen bonds- weak bonds that can be broken and reformed to allow the double-strand to be separated and read (transcribed). This means that if you have a strand of DNA and you want to separate the double helix to make more DNA, the two strands will have complementary sequences.
RNA and Amino Acids
The specific sequence of DNA nucleic acids (nucleotides) is transcribed into the sequence of nucleic acids of messenger RNA (mRNA); this