Compare and contrast eukaryotic DNA replication bubbles and

Compare and contrast eukaryotic DNA replication bubbles and transcription bubbles.

Solution

Answer:

Similarities:

1. Both replication and transcription is performed by large, multisubunit molecular machines (the replisome and RNA polymerase II, respectively)

2. Both require helicase activity at the fork of the bubble.

Differences:

1. Transcription bubble do not expand in both directions, i.e, proceeds in only one direction while replication bubble proceeds in both directions.

2. In transcription bubble, transcription takes place in only one DNA strand, while replication proceeds in both DNA strands.

3. Once the RNA is synthesized, the template DNA is immediately rejoined to its complementary strand. So, transcription bubbles are smaller (12-14 bases long).

4. No primers are required in the transcription bubbles compared to replication.

5. No okazaki fragments are formed as in replication bubble.