| A | B |
| enzyme changes shape to bind substrate | induced fit model |
| acts as a template to create RNA | antisense strand of DNA |
| it has the same sequence as RNA | sense strand of DNA |
| substitutes RNA primer with DNA | DNA polymerase I |
| adds a small fragment of RNA to lagging strand | primase |
| needed for transcription to begin | promoter |
| snRNP | Recognize splice site and help release the intron |
| exon | coding region of mRNA |
| intron | non coding region of mRNA |
| binds Okasaki fragments | ligase |