A Scientist Has Discovered A Human Gene From Cancer Cells

A Scientist Has Discovered A Human Gene From Cancer Cells The Nucleot

A scientist has discovered a human gene from cancer cells. The nucleotide sequence of the template strand of the gene was determined as written below: 3'gacacgtacgagcctggacaccttaagagcgggctcggaacactggccccgattgacac5'

(a) Study the nucleotide sequence of the template strand and write the sense strand (showing direction) of the gene.

(b) Write down the mRNA produced from this gene.

(c) How many amino acids will be present in the protein product of this gene?

(d) Write amino acid sequence of the polypeptide.

Paper For Above instruction

The investigation into the genetic makeup of cancer cells has led to the identification of a new human gene, with an emphasis on understanding its nucleotide sequence and the translation into functional proteins. The given nucleotide sequence of the template strand provides a foundation to explore the sense (coding) strand, the mRNA transcript, and ultimately, the amino acid sequence of the resulting protein. Here, we systematically analyze these components to elucidate the gene's functional translation potential.

(a) Determining the sense strand

The template strand of DNA is the antisense strand; it serves as the template for mRNA synthesis. The sense (coding) strand is complementary to the template and shares the same sequence, except for uracil replacing thymine in mRNA. Given the template strand:

3' GAC ACG TAC GAG CCT GGA CAC CTT AAG AGC GGG CTC GGA ACA CTG GCC CCG ATT GAC AC 5'

To find the sense strand, we align the complementary base pairs:

- Complementary pairing Rules:

- G pairs with C

- C pairs with G

- A pairs with T

- T pairs with A

Reading the template strand from 3' to 5', the sense strand will be complementary, and written from 5' to 3' (the usual direction).

Constructing the sense strand:

- Starting from the 5' end, the sense strand is:

5' G T C T G C A T G C T C G G A C C T G G T G G A A T C T C G C C C G A T C T G T G 3'

This sequence is the complement of the template strand, read 5' to 3'. Alternatively, to double-check, the process involves reversing the template strand to 5' to 3' and complementing each base.

(b) The mRNA transcript

The mRNA sequence is complementary to the template strand, but with uracil (U) replacing thymine (T).

Since the template strand is:

3' G A C A C G T A C G A G C C T G G A C A C C T T A A G A G C G G G C T C G G A A C A C T G G C C C C G A T T G A C A C 5'

The mRNA synthesis proceeds from 5' to 3' using the DNA template from 3' to 5', so the mRNA will be:

5' C U G U G C A U G C U C G G A C C U G U G G A A U C U C G C C C G A G C C U U G U G A C C G G G G C U A A C U G U G 3'

(c) Number of amino acids in the protein

The number of amino acids is determined by dividing the number of codons by three, excluding the stop codon.

- Count the number of nucleotides in the mRNA:

Number of nucleotides in the mRNA sequence: 66 nucleotides

- Calculate number of codons:

66 / 3 = 22 codons

- Therefore, there will be 22 amino acids in the polypeptide chain derived from this gene.

(d) Amino acid sequence of the polypeptide

Using the standard genetic code, each codon corresponds to a specific amino acid. The translation process involves grouping the mRNA into codons and then translating each codon.

Translating the mRNA (from the first codon):

1. CUG - Leucine (L)

2. UGC - Cysteine (C)

3. AUG - Methionine (M) (start codon)

4. CUC - Leucine (L)

5. GGA - Glycine (G)

6. CCU - Proline (P)

7. GUG - Valine (V)

8. GAA - Glutamic acid (E)

9. UCU - Serine (S)

10. CGC - Arginine (R)

11. CCG - Proline (P)

12. AGA - Arginine (R)

13. GCU - Alanine (A)

14. UGU - Cysteine (C)

15. GGU - Glycine (G)

16. GGC - Glycine (G)

17. UUA - Leucine (L)

18. GUA - Valine (V)

19. CUG - Leucine (L)

20. UGU - Cysteine (C)

21. GUG - Valine (V)

22. A - incomplete codon (since we have 66 nucleotides total, the last base is part of the final codon)

Note: The last nucleotide may be part of the last codon or may indicate a stop. Exact translation depends on the start codon and the open reading frame, but considering the entire chain, the amino acid sequence is as follows:

Amino Acid Sequence:

Leu-Cys-Met-Leu-Gly-Pro-Val-Glu-Ser-Arg-Pro-Arg-Ala-Cys-Gly-Gly-Leu-Val-Leu-Cys-Val

(Note: actual translation may vary slightly based on the correct reading frame choice, but this provides an approximation for the protein's amino acid sequence).

Conclusion

Translating a gene sequence involves understanding DNA complementarity, transcription into mRNA, and subsequent translation into amino acids. This specific gene has 66 nucleotides, translating into 22 amino acids, forming a polypeptide that potentially plays a role in cancer cell biology and could serve as a target for therapeutic intervention. Such molecular insights are crucial for advancing personalized medicine and targeted therapies.

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