Question

A template strand of DNA in a gene reads 3’ CCA AGC TCT 5’. Using the codon chart provided, answer the following questions:

Second letter U С A G UUU UỐC -Phe }Tyr U UCU UCC UCA UCG UAU2 UGU U UAC Ser UAA Stop UGA Stop A UAG Stop UGG Trp UGC}Cys DOCU UUA UUG Le eu С с CUU CUC CUA CUG Leu CCU ССС CCA CCG Pro CAUT His CAC CAA Gin CAG CGU CGC CGA CGG Arg a}G G First letter Third letter AGU A AUU ACU AUC lle ACC AUA ACA AUG Met ACG Thr AAU AAC AAA AAG AGC}Ser AGG}arg Docu AGA GAUT GUU GUC GUA GUG G Val GCU GCC GCA GCG GACAsp Ala GGU GGC *Gly GGA GGG GAA GAG с A G Glu

-What is the sequence of amino acids that is produced when this gene is translated?

-If a mutation causes a substitution (an A instead of a T) 3’ CCA AGC ACT 5’, what effect will it have on the mRNA transcript AND on the protein?

-What do we call this type of mutation?

Answer 1

Answer:

1.) Sequence of amino acid produced is:

Template strand	3'	CCA	AGC	TCT	5'
mRNA	5'	GGU	UCG	AGA	3'
Amino Acid	N	GLY	SER	ARG	C

2.) Below is the mRNA transcript and protein formed.

Template strand	3'	CCA	AGC	ACT	5'
mRNA	5'	GGU	UCG	UGA	3'
Amino Acid	N	GLY	SER	STOP	C

3.) This type of mutation is called non-sense mutation, as this mutation leads to premature synthesis of protein and causes loss of function of the protein. It is because of the termination codon that forms shorter amino acid chain.

Explanation: Template strand gets converted into mRNA via the process called transcription.

- Then, during translation amino acid chain are formed from triplet codon formed from this mRNA transcript. This amino acid chain formation leads to functional protein formation.

- The conversion of DNA to mRNA follows this conversion pattern: A-U, T-A, G-C, C-G.

- Then the triplet codon of mRNA follows the genetic codon table provided to form amino acid.

- The mutation mentioned is due to non sense codon which leads to formation of non functional protein.