Question

8. Draw chemical structure of a double strand DNA molecule of following DNA template S'CT3. Include the phosphodiester and all hydrogen bonds. (7) 9. If you cut the following double stranded DNA fragment with a restriction enzyme with restriction site of 5'GAATTC 3" and the cutting point between A and G. Draw the structure of resulting fragments. Specify and name the end of the fragments. (8) 5" ACCTTGTGAATTCTAGGCAT3 3' TGGAACACTTAAGATCCGTAS

Answer 1

8. Dna is a double helix structure, each necleotide pairs with a complimentary nucleotide via hydrogen bond. Cytosine pairs with Guanine and Thymine pairs with Adenine. For a DNA template, 5- CT -3', it will pair with 3'- GA -5'. The structure of DNA will be

The dotted lines the figure represents hydrogen bond.

NH2 Cytesine Guanime Phaspho diestex bo md Phosphata Adenime Tkymime

9. The restriction enzyme has restriction site of 5'- GAATTC -3' and it cleaves the DNA strand between A and G.

So, In the given DNA fragment given,

5- ACCTTG TG AATTCTAGGCAT -3' 3'-TGGAACACTTAAG AT CC GTA T - s' SA ATT CTA GGCAT-3' 3'- GATCCGTA -5' s- ACCTTGTG-3 3- TGGA ACACTTAAS 2 Frag ments.