RNA polymerase: Group of answer choices

1. can synthesize RNA chains without a primer.
2. binds tightly to a region of DNA thousands of base pairs away from the DNA to be transcribed.
3. has a subunit called lambda, which acts as a proofreading ribonuclease.
4. separates DNA strands throughout a long region of DNA (up to thousands of base pairs), then copies one of them.
5. synthesizes RNA chains in the 3' -> 5' direction.

1

Explanation:

RNA polymerase is an important enzyme of gene expression as it is actively involved in the transcription process, which is the synthesis of a complementary strand of mRNA from a DNA template. RNA polymerase starts the transcriptional process by binding to the promoter region of the gene on the DNA. This signals the unwinding of the double-stranded DNA molecule, the enzyme then uses the a single separated strand to add nucleotide bases complementary to the ones on DNA, to the growing RNA molecule.

This process of transcription is somewhat similar to what occurs in DNA replication catalyzed by DNA polymerase, but unlike DNA polymerase, RNA polymerase does not require a primer to work with in its synthesis of

RNA nucleotides in a 5'-3' direction.