Question

Genetics

To answer the prompts below, you will need to draw the chemical structure of the trinucleotide 5' - TCA - 3', labeling the 5' and 3' ends. Opposite this structure, draw the complementary trinucleotide to make a double-stranded DNA molecule.

a. What is the complementary trinucleotide sequence from 5' to 3' (enter answer e.g. CGA)   

b. How many non-covalent hydrogen bonds stabilize this structure?  

c. How many covalent phosphate linkages stabilize this structure?   

Answer 1

H-bond (3 Hydroxyl group) 5) Phosphate o-P-O- CH, Phoophoestor linkages. Phosphoester bond PO H cytosine Phosphodiestes band -CH2 opo HV Adenine OH H 3) sychoryl group T 5'phosphate end) H-bond- Phosphodiester bend (a.) Complementary trinucleotide sequence of ICA' will be 'AGT' as thy mine binds to adenine and cytosine to guanine. (6) T=A (=G; A=T So, there are 2+3+2 = 7 hydrogen bonds in the TCA trinucleotide, when complementary strand is present. .(c) There are 5 Phosphate unkages in each strands, so total to phosphate Unkages. stabilise the structure. Note: - Bonds are labelled by red pens, - Name of nitrogenous bares are circled with frost letter. eg., Adenine - o