Chemical Nature of the Gene

Watson-Crick model

discovery of DNA double helix structure

DNA replication

copies DNA before cell division

Mutation

change in DNA sequence

Protein synthesis

process of making proteins

Structural genes

code for body structure proteins

Regulatory genes

control gene activity

Transformation

bacteria take DNA from environment

Transduction

virus transfers DNA between bacteria

Viruses

non living particles that infect cells

Chromatin

loose DNA before replication

Chromosome

condensed DNA form

Nucleosome

DNA wrapped around histones

Histones

DNA packaging proteins

Base pairing rule

A pairs with T and C pairs with G

DNA double helix

twisted ladder structure of DNA

DNA blueprint

contains instructions for proteins

Helicase

enzyme that unzips DNA

DNA polymerase

builds new DNA strand

Template strand

DNA strand used for copying

Replication result

two identical DNA molecules

Mutation causes

replication errors or radiation

Substitution mutation

one base replaced by another

Frameshift mutation

base added or removed

Transcription

DNA to RNA process

Translation

RNA to protein process

mRNA

messenger RNA carrying genetic code

Codon

three RNA bases

Anticodon

matching sequence on tRNA

tRNA

brings amino acids to ribosome

Ribosome

makes proteins

Structural proteins

build body parts and cells

Regulatory proteins

control gene expression

Bacterial transformation

DNA taken from environment

Transduction

DNA transfer by viruses

Virus

non living particle with genetic material

Virion

individual virus particle

Capsid

protein coat of virus

Viral infection

virus takes over host cell

Host cell

cell infected by virus

Viral replication

host makes new viruses