Unit 3b: DNA

Double Helix

"Twisted ladder;" shape of DNA

Hydrogen Bonds

Bonds that hold together the two sides of a DNA molecule

Sugar-Phosphate Backbone

The structural part of the DNA molecule

Complementary Base Pairing

Rule that only certain bases will bond with each other in DNA

Codon

A set of three nitrogen bases that codes for an amino acid

Transcription

Part of protein synthesis that makes mRNA from the DNA code

Translation

Part of protein synthesis that makes the protein using the mRNA sequence

mRNA

Takes the DNA code to the ribosome

tRNA

Brings amino acids to the ribosome

rRNA

Helps to make up the ribosome

Peptide Bond

Bonds between amino acids in a protein

Polypeptide

Another term for a protein

Differentiation

Cells activate different genes to turn into certain cell types

Embryonic Stem Cell

Stem cells that can turn into any cell type

Adult Stem Cell

Stem cells that can turn into only certain cell types

Mutation

Change in a DNA sequence

Mutagen

Something that can mutate DNA

Point Mutation

A substitution of one base for another in a DNA sequence

Frame-Shift Mutation

An addition or deletion in a DNA sequence that changes the "reading frame"

Inversion Mutation

When a section of DNA "flips" itself