A fragment of double-stranded DNA is given below: 3' - T A C G C A A T C G - 5' | | | | | | | | | | 5' - A T G C G T T A G C - 3' Calculate the total number of nitrogen atoms present in this DNA fragment.

Question

Accepted Answer

Given options are blank — this is a numerical answer type. Top strand (3'→5'): T-A-C-G-C-A-A-T-C-G. Bases: T=3, A=3, C=3, G=2 (counting: T,A,C,G,C,A,A,T,C,G → T:3, A:3, C:3, G:2... let me recount: T(1),A(2),C(3),G(4),C(5),A(6),A(7),T(8),C(9),G(10) → T:2, A:3, C:3, G:2). Bottom strand (5'→3'): A-T-G-C-G-T-T-A-G-C → same composition reversed: A:2, T:3, G:2, C:3... recount A(1),T(2),G(3),C(4),G(5),T(6),T(7),A(8),G(9),C(10) → A:2, T:3, G:3, C:2. Combined both strands: T_total = T(top)+T(bottom) = 2+3=5, A_total = A(top)+A(bottom) = 3+2=5, C_total = 3+2=5, G_total = 2+3=5. N atoms: A*5 + T*2 + G*5 + C*3 = 5*5 + 5*2 + 5*5 + 5*3 = 25+10+25+15 = 75. Total N = 75.

A fragment of double-stranded DNA is given below: 3' - T A C G C A A T C G - 5' | | | | | | | | | | 5' - A T G C G T T A G C - 3' Calculate the total number of nitrogen atoms present in this DNA fragment.

Solution

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