DNA, Protein Synthesis and Heredity

terminology

DNA• Deoxyribonucleic acid• Two strands• Found in nucleus of eukaryotic cell• Found in cytoplasm of prokaryotic cell• Contains instructions for making an

organism’s proteins• Shaped like double helix- twisted ladder

RNA• Ribonucleic acid• One strand• Contains the base uracil instead of

thymine• Two types of RNA- messenger and

transfer• Contains the sugar- ribose

Messenger RNA• The type of RNA that carries the coded

message from the nucleus to the cytoplasm

Transfer RNA• Type of RNA that carries an amino acid to the

ribosome and adds it to the growing protein chain

DNA Replication

• The process by which DNA makes a copy of itself

Mutation• A change in the order of the bases in an organism’s DNA• There are three types of mutations: insertion, deletion, substitution

Mutagen• A substance or agent that can damage or

cause changes to DNA• Radiation is a one environmental mutagen

that may cause direct changes in a cell's DNA. For example: X-rays can break DNA sequences in many places, leading to chromosome rearrangement.

DNA BASES• A base is a part of a nucleotide- which is

a subunit of DNA• Bases make up the rungs of the ladder in

DNA• There are 4 bases: cytosine, guanine,

adenine and thymine

Chromosome

• A coiled structure of DNA and protein that

Meiosis• Cell division that produces sex cells

Four unique daughter cells from one parent cellEach daughter cell contains half the number of chromosomes as the parent cell

Pedigree

• A tool used to trace a trait through several generations of a family

Carcinogen

• A substance or agent that can cause cancer