2.1 DNA Replication I

What was the main reason that scientist thought that semi-conservative replication was impossible?

Bc DNA is plectonemic

What does plectonemic mean? In DNA

Strands can’t be separated without unwinding the Double helix structure

What are some examples of circular DNA?

Bacterial DNA / human mitochondria DNA / DNA viruses / Plasmids

What are DNA supercoils?

Produced if strands are separated

What can help remove or prevent DNA supercoils?

Enzyme DNA topoisomerase

What does the type 1 DNA topoisomerase do?

Cut one strand of the double stranded DNA

What does the type 2 DNA isomerase do?

Cut both strands of the double stranded DNA

What is buoyant density?

Density possessed by a molecule or particle when suspended in an aqueous salt or sugar solution

What is DNA topoisomerase?

Enzyme that introduces or removes turns from the double helix by breakage and reunion of one or both polynucleotides

What is the G segment?

DNA strand that’s the type II topoisomerase cuts completely so the other strand (T segment) can pass through

What is the T segment?

DNA strand that the type II topoisomerase keeps intact and passes through the cut G segment

What is type I topoisomerase?

A tropoisomerase that makes a single-stranded break in a double stranded DNA molecule

What is type II topoisomerase ?

A tropoisomerase that makes a double-stranded break in a double-stranded DNA molecule.