Central Dogma of Molecular Genetics

Question

1. Assuming the presence of the complementary strand , what is the percentage composition of the polymer with respect to the A-T base pair and with respect to the C-G base pair?

2. In the given statement, illustrate and indicate the direction synthesis of

A.) a 5-nucleotide of RNA primer

B.) s 2 nucleotide of Okazaki fragment

Answer 1

1. Without a reference image, it is impossible to give actual percent compositon of the DNA polymer. However, given the nature of complimentary base pairing, the percentage of A and T are always the same, and the percentage of C and G are always the same, and the total percentage must add to 100.

If you know the percentage of one nucleotide, then you can calculate them all. For example, if the percentage of A is 10, then T must also be 10. This would leave 80% to be divided equally between the remaining G and C nucleotides, or 40% each.

1. DNA and RNA polymerase always adds new nucleotides to the 3' end of the polymer, so the direction of synthesis is always 5' --> 3'. However, the Okazaki fragments are made on the lagging strand, which gives the appearance of elongating in the 3' --> 5' direction, but this is just an illusion. The lagging strand grows 3' --> 5' in short 5' --> 3' leapfrogging bursts.