DNA and Genes Prokaryotes VS Eukaryotes Prokaryotes no

DNA and Genes

Prokaryotes VS Eukaryotes • Prokaryotes: no defined nucleus and a simplified internal structure • Eukaryotes: membrane limited nucleus and complicated internal structure

• Genetic material is located in nucleus • The genetic information is stored in Deoxyribonucleic acid, DNA • DNA contains the information needed to build an individual

What is DNA needed for? • Genetic information is copied from DNA and converted to protein • RNA molecules work as messengers that carry the info to the ribosomes. • Proteins are the biological workers.

DNA (Deoxyribo Nucleic Acid) DNA is two long chains of Nucleotides • A Nucleotide consists of: • A phosphate Group • A five carbon sugar (deoxyribose) • A Nitrogenous Base

DNA • The sides of the DNA strand are the connection of the Phosphates to the Sugars. • Each Phosphate is connected to deoxyribose by a covalent bond.

DNA • There are four bases that make up the “rungs” of the ladder • Adenine • Guanine • Cytosine • Thymine

Four bases. . . Each of the four bases has a specific shape. Purine bases • Adenine and Guanine • Two carbon rings Pyrimidine bases • Thymine and Cytosine • A single carbon ring A two carbon ring can only attach to a single carbon ring.

DNA • Each base pair is held together by a hydrogen a couple of hydrogen bonds.

Base Pairing Rule • Adenine only pairs with Thymine and Cytosine only pairs with Guanine. • They are called complimentary base pairs.

DNA Molecules • Two polynucleotide chains are joined • Double helix, twisted in right handed way • Full circle in every 10 bases

The Genetic Code • Describes how nucleotide sequence is converted to protein sequence • Unit of three nucleotides = a codon • A codon codes for a specific amino acid (structural component of protein)