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predict the outcome of a mutation where the codon CUC is changed to AUC. Be sure

ID: 175935 • Letter: P

Question

predict the outcome of a mutation where the codon CUC is changed to AUC. Be sure to include what amino acids are being exchanged. (HINT: compare and contrast the structures)
predict the outcome of a mutation where the codon CUC is changed to AUC. Be sure to include what amino acids are being exchanged. (HINT: compare and contrast the structures)
predict the outcome of a mutation where the codon CUC is changed to AUC. Be sure to include what amino acids are being exchanged. (HINT: compare and contrast the structures)

Explanation / Answer

ANS:

It is a point mutation. The change of a single nucleotide in a DNA’s template strand leads to produce an abnormal protein.

A point mutation is a failure of by the replicating the cell to copy the genetic information accurately. Point mutation may be beneficial, harmful or neutral (having no effect on the organism)

A point mutation is classified into 3 major types. They are…

1. Substitution point mutation: Change of a nucleotide or few nucleotides from one type to another.

2. Insertion point mutation: An insertion of one or few nucleotides in the DNA sequence.

3. Deletion point mutation: A deletion of one or few nucleotides in the DNA sequence.

In the point mutation one base is substituted for another, 3 possible consequences are possible..

A. Non- sense mutation: Codes for a stop, which can translate the protein.

B. Miss-sense mutation: Codes for different amino acid.

C. Silent mutation: Code for the same amino acid.

According to the given question it is a Miss-sense mutation.

Miss-sense mutation:

Miss-sense mutation that results in an altered codon that codes for a different amino acid.

In Miss-sense mutation one gene affect only the conserved enzyme. Therefore there mutons were used to assign the three enzymes to the three structural genes.

A missense mutation in

1. Lac opern -Z affects -Galactose

2. Lac opern -Y affects Permease

3. Lac opern -A affects Trans acetylone.

Normal m-RNA Sequence:

Effect introducing in m-RNA Sequence:

MRNA SEQUANCE: AUG   UUG UCA AAA CUC UGG CGG CCA

AMINO ACIDS:          met    leu        ser     lys       Leu      trp       arg     pro

After a single nucleated replaced (A instead of C in CUC)

MRNA SEQUANCE: AUG UUG UCA AAA AUC UGG CGG CCA

AMINO ACIDS:             met   leu ser       lys ILE trp arg pro

Effect: Incorrect amino acid which may produce a MALFUNCTIONING protein.