Question

5'-tatctatggcatggcgatcatagaggcgtg-3'

3'-atagataccgtaccgctagtatctccgcac-5’

a. Write the mRNA sequence for this gene. Be sure to label the 5’ and 3’ ends. (2 pts.)

c. Circle the start and stop codons in the sequence you wrote in b. (2 pts.)

d. Write the protein sequence translated for this gene. (2 pts.)

e. The anticodon of the tRNA which carries the last amino acid will be: ____________ (2 pts.)

2. Write one sentence using the words promoter, transcription factors and RNA polymerase to describe the relationship between these three components of transcription.

(3 pts.; one point for use of each word correctly)

4. What are two functions of the 5’ cap and the poly A tail on a mature mRNA molecule? (2 pts. for each function; 4 pts. total)

5. In the DNA template strand a codon on the template strand is changed from 3’TTG-‘5 to 3’TTA-5’.

a. What is(are) the amino acid(s) coded for before and after the change? (2 pts.)

b. Does the change from 3’-TTG-5’to 3’-TTA-5’ make a difference in the protein produced? (2 pts.)

Please help this is the last biology assignment I ever have to do and I am on the verge of tears.

c. What if the new codon was a 3’-TTT-5’? Would this make a difference in the protein structure? Explain your answer. (2 pts.)

Answer 1

Ans1)

Ans a) The mRNA sequence for the gene

5’ – UAUCUAUGGCAUGGCGAUCAUAGAGGCGUG- 3’

This is the mRNA sequence which is formed from the DNA and it is labelled from 5’ to 3’ end. Also the Adenine is complementary to uracil and guanine is complementary to cytosine.

Ans b) AUG is the start codon and UAG is the stop codon. The start codon is the first codon with the messenger RNA where the ribosome starts with the translation process. It is basically a methionine amino acid. The stop codon is UAG where the process of translation stops.

Ans d) The protein sequence which is translated from this is

Met – Arg – Trp – Arg – Ser – Stop

The translation starts with the start codon and stops at the stop codon and this is the amino acid sequence which is formed from the mRNA.

Ans e) The anticodon of the tRNA which will carry the last amino acid is UAG. And this is the stop codon post which the translation will stop