1/ This is typically something you won't see covered in genetics. You usually get into this in Virology, but I think it is important to understand now. This is about the different types of polymerases and what they do.
2/ The polymerase functions by building chains of nucleotides to form RNA or DNA chains. There are 4 basic kinds of polymerase based on what type of genetic code they read and what type of genetic polymerase they create. 
3/ The first is the DNA dependent DNA polymerase. It reads DNA and it creates DNA. Our human DNA polymerase that synthesizes our DNA or does DNA repair comes from this family.
4/ You will often see the DNA polymerase referred to by its Greek alphabet name such as DNA pol Theta. There are several of these DNA polymerases working in human cells. They all have different functions.
5/ The second kind of polymerase is the DNA dependent RNA polymerase. This is what we typically call the RNA polymerase in human cells. It copies the DNA into RNA.
6/ The DNA to RNA polymerases come in 3 kinds in humans with RNA polymerase I making ribosomal RNA, polymerase II makes the messenger RNA, and polymerase III makes the transfer RNA.
7/ The third kind of polymerase is RNA dependent DNA polymerase. This is typically called the Reverse Transcriptase. It takes RNA and can write it into DNA to inset into the genome. You see this in retro viruses like HIV.
8/ There are several of these reverse transcriptase used in biotech right now with Lentivirus and Gamma Retroviruses. They use them to do basic cell editing in the lab.
9/ The last polymerase is the RNA dependent RNA polymerase. This is not natural to human cells. Its used by viruses to copy their RNA genome into more viral genome or messenger RNA in human cells.
10/ The viral RNA to RNA polymerases are also targets of anti viral therapies.
• • •
Missing some Tweet in this thread? You can try to
force a refresh
