During transcription, when RNA nucleotides form base pairs with the DNA template, does this mean that RNA nucleotides and DNA nucleotides pair up?
Yes, during transcription, RNA nucleotides do form base pairs with the DNA template. However, it's important to note that RNA nucleotides do not actually pair up with DNA nucleotides directly. Instead, they form base pairs through complementary base pairing.
In DNA, the four nitrogenous bases are adenine (A), thymine (T), cytosine (C), and guanine (G). During transcription, a specific enzyme called RNA polymerase binds to the DNA template strand and moves along it, synthesizing a new RNA strand. However, in RNA, thymine is replaced by uracil (U). So, during transcription, RNA nucleotides pair with specific DNA nucleotides as follows:
- Adenine (A) in DNA pairs with uracil (U) in RNA
- Thymine (T) in DNA pairs with adenine (A) in RNA
- Cytosine (C) in DNA pairs with guanine (G) in RNA
- Guanine (G) in DNA pairs with cytosine (C) in RNA
By following these complementary base pairing rules, the RNA polymerase synthesizes an RNA strand that is complementary to the DNA template strand.
Yes, during transcription, RNA nucleotides indeed form base pairs with the DNA template. However, it is important to note that RNA nucleotides are not exactly the same as DNA nucleotides. While both types of nucleotides have a sugar-phosphate backbone and contain a nitrogenous base, the sugar component in RNA is ribose, whereas in DNA it is deoxyribose. Additionally, the nitrogenous base uracil (U) is found in RNA, whereas thymine (T) is found in DNA instead.
During transcription, the DNA double helix is unwound and separated to expose the template strand. RNA polymerase synthesizes a complementary RNA strand by adding RNA nucleotides that base pair with the exposed DNA template strand. The pairing follows the same Watson-Crick base-pairing rules: adenine (A) pairs with uracil (U), and cytosine (C) pairs with guanine (G).
To summarize, RNA nucleotides and DNA nucleotides do not pair up directly during transcription. Instead, RNA nucleotides form complementary base pairs with the exposed DNA template strand, utilizing the correct base pairing rules.