Transcription

Introduction

The cells in the body contain a complete copy of a person’s genetic plan contained in our DNA. The DNA is arranged in genes that are part of chromosomes. The genes contain information necessary for our bodies to grow and work. The information in the genes is in the form of a chemical code, called the genetic code. Each gene contains the code to make a message to tell cells how to make a particular product such as a protein. My paper will focus on the genetic code and the effects of mutations. Our own genetic code, simplified is a two step process called transcription and translation. Transcription happens when a 3 base DNA sequence transfers information to its complementary 3 base sequence in mRNA. Translation is the information carried by the mRNA molecule, also called a codon, and is decoded into an amino acid used to make polypeptides. Mutations that disrupt the 3 base sequence by inserting a different nucleotide or deleting one altogether may lead to a change in the amino acid sequence. If the change does alter the sequence of a specific amino acid and alters its ability to function normally then these mutations are called overt. On the other hand, some mutations do not change the sequence. The mutated codon still codes for the original amino acid and so the mutation is called silent. Mutations are not necessarily bad, many are nature’s way or varying our gene pool through natural selection while the good mutations tend to hang around and result in positive evolutionary changes. My hypothesis states that “most mutations are of the silent nature”.

Materials

1. DNA nucleotide sequence sheet

2. Genetic Code Reference Guide

3. Paper bag with the letters U,C,T,G,A

Method

First I made a DNA sequence sheet. I then simulated transcription by entering the correct RNA nucleotide sequence to form the mRNA. Once this was completed I used the Genetic Code Reference table to find the appropriate amino acid for the matching RNA codon. I wrote this information on the sheet also. Next to