Just need help.
Question:
One strand of DNA is completely transcribed into RNA by RNA polymerase. The base composition of the DNA template strand is: G =20%. C=25%, A=15%, and T=40%. What would you expect the composition of the newly synthesized RNA to be?
What makes up a nucleotide? What are the four component bases of DNA? How do the bases of Does RNA differ from DNA? the specific bases pairings for each?
To determine the composition of the newly synthesized RNA, you need to understand the process of transcription and the base-pairing rules.
During transcription, RNA polymerase adds nucleotides to form an RNA molecule that is complementary to the template DNA strand. The RNA bases are adenine (A), cytosine (C), guanine (G), and uracil (U), which replaces thymine (T) in RNA.
The base-pairing rules are as follows:
- Adenine (A) pairs with uracil (U) in RNA instead of thymine (T) in DNA.
- Cytosine (C) pairs with guanine (G), just like in DNA.
In this case, the given DNA template strand composition is: G = 20%, C = 25%, A = 15%, and T = 40%.
To determine the composition of the newly synthesized RNA, you can assume that the percentages of bases in DNA will be reflected in the percentages of their complementary bases in RNA.
So, if T = 40% in DNA, then A (complementary base) would also be 40% in the newly synthesized RNA.
If G = 20% in DNA, then C (complementary base) would also be 20% in the RNA.
If C = 25% in DNA, then G (complementary base) would also be 25% in the RNA.
Lastly, if A = 15% in DNA, then U (complementary base) would also be 15% in the RNA.
Therefore, you would expect the composition of the newly synthesized RNA to be: A = 40%, C = 20%, G = 25%, and U = 15%.