DNA structure and replication

TGAC

Bases in DNA

UGAC

Bases in RNA

Thymine

The base that pairs with Adenine in DNA

Guanine

The base that pairs with Cytosine in DNA

Nucleotide

Monomer of DNA

ribose sugar, phosphate group, nitrogenous base

The three components of a nucleotide

hydrogen bond

Weak bond that bonds bases together across the rungs of the DNA ladder

covalent bond

bond that bonds sugars and phosphates along the backbone of DNA

semi-conservative replication

in each new DNA double helix, one strand is from the original molecule, and one strand is new

DNA

A double helix containing the genetic information that makes up the chromosomes.

RNA

single-stranded nucleic acid that carries genetic messages

DNA polymerase

Enzyme involved in DNA replication that joins new nucleotides onto the growing molecule

Helicase

An enzyme that untwists the double helix of DNA at the replication forks.

replication bubble

Segment of a DNA molecule that is unwinding and undergoing replication.

Ligase

An enzyme that connects two fragments of DNA to make a single fragment

Okazaki fragments

Small fragments of DNA produced on the lagging strand during DNA replication, joined later by DNA ligase to form a complete strand.

double helix

Shape of DNA

complementary

completing; fitting together well