Functions of proteins involved with DNA Replication, Transcription, and Translation
a. DNA Helicase:
i. Unwinds the DNA helix
ii. Separates the DNA bases during DNA replication or transcription
b. Single strand binding proteins:
i. Binds to DNA and keeps the bases pairs from rejoining
1. Keeps the DNA single stranded for a short period of time
c. DNA Primase:
i. Adds a primer of RNA to begin DNA replication
d. DNA polymerase:
i. Adds new DNA nucleotides (to create a DNA polymer) to the 3’ end of DNA or RNA during
replication
ii. Removes the RNA primer
iii. Proofreads the bases pairing mistakes that may have occurred during replication
e. DNA Ligase:
i. Attaches Okazaki fragments (LIGANDS of DNA) once the RNA primers have been replaced by
DNA
f.
Telomerase:
i. Adds telomeres to the ends of DNA to prevent the loss of genes during replication
1. Telomeres are repetitive sections of DNA that do not code for proteins
2. Telomeres tend to be lost during replication
g. Topoisomerase:
i. Prevents overwinding or underwinding of DNA so that replication or transcription can continue
1. Topo = topographical (topographic maps show the hills and valleys of a piece of land)
2. Isomer = Same chemical formula different structure
a. Each DNA molecule made of the same chemical will have different physical
appearances based on how it wraps on itself.
h. RNA Polymerase:
i. Adds new RNA nucleotides (to create a RNA polymer) to the 3’ end of RNA during transcription
Remember to read each words or set of words in reverse order.



ASE = enzyme
Helix = twisted molecule
DNA = DNA
o DNA Helicase when read in reverse is an enzyme that unwinds and separates the helix of DNA
The words that are highlighted in RED on this page are meant to
help you learn the material.