Chapter 16, Problem 67P

(a)

Interpretation Introduction

Interpretation:

The anti-codon on tRNA that should pair with UUG tRNA codon should be determined.

Concept Introduction:

The mRNA strand is arranged in a series of three (3) bases long units called codons. Each codons code for an amino acid. Corresponding to each unit of three (3) bases on the mRNA bo0und to ribosome, there is a complimentary set of three bases called anticodon, situated on the arm of tRNA molecule directly opposite to the arm that binds the amino acids. Marshall Nirenberg and Henrich Matthaei experimentally showed that by using a synthetic RNA chain consisting of only one type of base (uracil) a polypeptide chain containing only one type of amino acid, phenyl alanine is produced.

Thus, the base sequence UUU is the recognition site of phenylalanine. Similar model experiments with synthetic RNA molecules containing the other bases have yielded the entire RNA codes for all the 20 naturally occurring amino acids. Thus, the base sequence AUG-UUU-CAG-ACC-AAA in mRNA corresponds to the amino acid sequenceSeveral of the 64 combinations of these four (4) RNA bases (A, C, G, U) into groups of three to recognise only twenty (20) amino acids are redundant and do not code any amino acid signals the start and end of protein synthesis.

(b)

Interpretation Introduction

Interpretation:

The anti-codon on tRNA that should pair with CAC tRNA codon should be determined.

Concept Introduction:

The mRNA strand is arranged in a series of three (3) bases long units called codons. Each codons code for an amino acid. Corresponding to each unit of three (3) bases on the mRNA bo0und to ribosome, there is a complimentary set of three bases called anticodon, situated on the arm of tRNA molecule directly opposite to the arm that binds the amino acids. Marshall Nirenberg and Henrich Matthaei experimentally showed that by using a synthetic RNA chain consisting of only one type of base (uracil) a polypeptide chain containing only one type of amino acid, phenyl alanine is produced.

Thus, the base sequence UUU is the recognition site of phenylalanine. Similar model experiments with synthetic RNA molecules containing the other bases have yielded the entire RNA codes for all the 20 naturally occurring amino acids. Thus, the base sequence AUG-UUU-CAG-ACC-AAA in mRNA corresponds to the amino acid sequenceSeveral of the 64 combinations of these four (4) RNA bases (A, C, G, U) into groups of three to recognise only twenty (20) amino acids are redundant and do not code any amino acid signals the start and end of protein synthesis.