DNADNA(deoxyribonucleic acid)(deoxyribonucleic acid)

Primary Roles of DNAPrimary Roles of DNA

Store InformationStore Information Copy InformationCopy Information

– A cell must make a complete copy of its A cell must make a complete copy of its DNA before the cell divides DNA before the cell divides

Transmit InformationTransmit Information– DNA molecules must be carefully sorted DNA molecules must be carefully sorted

and passed along when cells divideand passed along when cells divide

VocabularyVocabulary

Nucleic acid – molecule that is Nucleic acid – molecule that is essential for lifeessential for life–Long molecule found in a cell’s Long molecule found in a cell’s

nucleusnucleus

– Made of smaller subunitsMade of smaller subunits

– Examples are DNA and RNAExamples are DNA and RNA

Vocabulary (cont.)Vocabulary (cont.)

Nucleotides Nucleotides –Have 3 partsHave 3 parts

A 5-carbon sugar (deoxyribose or A 5-carbon sugar (deoxyribose or ribose)ribose)

A phosphate groupA phosphate groupA base that contains Nitrogen A base that contains Nitrogen

–Adenine, Guanine, Cytosine, ThymineAdenine, Guanine, Cytosine, Thymine

Structure of DNAStructure of DNA

Nucleic acid made of Nucleic acid made of nucleotidesnucleotides

Double helix model Double helix model – Looks like a twisted ladderLooks like a twisted ladder

Base pairing – bonds in Base pairing – bonds in DNA can form only DNA can form only between adenine and between adenine and thymine or between thymine or between guanine and cytosineguanine and cytosine