Chapter 22, Problem 63P

Interpretation Introduction

Interpretation:

Using the given DNA template strand, the transcribed mRNA sequence and the polypeptide that would be synthesized from this template should be filled in.

Concept Introduction:

Conversion of genetic information in DNA into mRNA is called transcription. The DNA strand from the DNA double helix which is used for mRNA synthesis is the template strand. Transcription proceeds from 3' end to 5' end. Complementary base pairing determines which nucleotide should add to the growing chain of mRNA.

This mRNA strand provides code for the synthesis of polypeptide chain with 20 different amino acids. A sequence of three nucleotides which is called a codon codes for a specific amino acid. There are 4 types of nucleotides found in RNA strand which are A, C, G and U. These four nucleotides can be combinedin 64 different ways to make codons with three nucleotides. From these, only 61 codes for amino acids. Other three does not correspond to any of the amino acid, so, they are called stop codons.