Unit 11 Flashcards
Untwists the double helix at the replication fork & separates the 2 parent strands into templates
Helicase
Corrects “overwinding” ahead of replication fork by breaking, swiveling, & rejoining DNA strands
Topoisomerase
Puts the fragments together on the lagging strand (link, glue)
DNA Ligase
Enzyme that looks for mistakes, cuts them out, and repairs them before they mutate
Nuclease
Messenger
RNA primer
Enzyme that helps the initial nucleotide primer strand of RNA
RNA primase
Starts RNA chain from scratch / we need it b/c DNA can’t start its process
RNA primase
Binds to & stabilizes single stranded DNA until it can be used as a template
Single strand binding protein
Where is this the double helix credited from?
Watson & Crick
What are the back bone ladders of the double helix made of?
repeating phosphate sugars
What are the 4 nitrogen bases?
Adenine, Guanine, Thymine, Cytosine
What is equivalent to one unit?
1 phosphate group, 1 nitrogen base, 1 sugar
Between nitrogen bases, how is DNA held together?
Hydrogen bonds
What are hydrogen bonds the most practical bonds for this?
Stable enough to hold together DNA, weak enough to split apart, replicate, then come back together
how many bonds to G & C have?
3
How many bonds do A & T have?
2
What type of bond holds together the back bone?
Covalent (strong)