Question

21-1114 Date Transcription Kit Checklist Part 1: Making mRNA 1. Parts of a nucleotide: Approved Sugar Phosphate Bases: Adenine Guanine Cytosine Uracil 2. One nucleotide Note: Omit 3-6 if not using the DNA Structure and Function Kit. 3. Separated DNA 4. Template DNA with one complementary nucleotide of RNA hydrogen bonded 5. Template DNA with strand of mRNA hydrogen bonded 6. Separated mRNA and duplex DNA molecule 7. Completed mRNA with cap and tail 8. The cap 9. The tail Part II: Point Mutation 10. What two unusual features of the attached methyl guanosine cap can you o

Answer 1

1 At 5'end of mRNA capping is made

2 the tail placed in 3' end of the mRNA

5' cap--------------------AAAAA 3'

Capping PolyA tail

3 the amino acid sequence for given mRNA is

Methionine-glycine -glutamic acid- Alanine

4 UGA is a stop codon which is used for stopping the protein synthesis. As the ribosomes reaches the stop codon the protein synthesis is stopped.

5 ccc-ccu, these two codons codes for the same amino acid proline. So there is no chang in amino acid.

Similarly uau-uac codes for tyrosine. So, there is no change in coded amino acid.

Cau-cgu causes change in amino acid. Cau codes for histidine and cgu codes for Arginine. Therefore the answer is yes with regard to change in amino acid.

6 point mutation are type of mutation caused by change in single nucleotide base. As seen in the above answer first two pair nucleotide codons change does not cause change in amino acid. So there is no change in protein sequence and function so it is not harmful. This kind of mutation is known as silent mutation since there is no notable effect.

Some mutation like in third example change in amino acid causes change in sequence and biological function. Change in function or loss of function results in harmful condition.

It may be nonsense mutation, if point mutation results in coding stop codon eg-UAC-UAA , misense mutation result in same amino acid of different codon. Eg:CAU-CGU