DNA

Structure/Function

RECALL…

4 classes of macromolecules– Carbohydrates– Lipids– Proteins

–NUCLEIC ACIDS!!!–Subunit: NUCLEOTIDES

Nucleic Acid Examples

• DNA – deoxyriboNUCLEIC ACID(de – without, oxy – oxygen, ribo – ribose sugar)

• Store and pass genetic information• Code for proteins

• RNA – riboNUCLEIC ACID• Protein synthesis

• Subunits of DNA/RNA: nucleotides

DNA

• Very longVery long thin molecule made up of linked nucleotides

• Double stranded helix– Twisted ladder

• Determines traits of EVERY LIVING ORGANISM

Nucleotide Structure

• 3 parts– Sugar (deoxyribose or ribose)– Phosphate (P with oxygens attached)– Nitrogen base

• Adenine• Thymine• Guanine• Cytosine

Nucleotide Structure• 2 classes of nucleotides

– Purines

• Adenine

• Guanine

– Pyrimidines

• Thymine

• Cytosine

Purines are PURE – like

AnGels

Pyrimidines –

Y like Thymine

and Cytosine

Nitrogen Base Pairing

Adenine Thymine

4-evaGuanine Cytosine

Nitrogen Base Pairing

Adenine Thymine

Guanine Cytosine

= Hydrogen Bond

Nitrogen Base Pairing

Adenine ThymineCytosine GuanineThymine AdenineCytosine GuanineCytosine GuanineAdenine Thymine

Guanine Cytosine

= Hydrogen Bond

Nitrogen Base Pairing

Adenine ThymineCytosine GuanineThymine AdenineCytosine GuanineCytosine GuanineAdenine Thymine

Guanine CytosineSugar + Phosphate backbone

• Compl-e-ment – complement– To complete, finish, or fill something up

NOT this kind…

• Compl-i-ment - compliment– “My students are the best in the school!”

What is the COMPLEMENTARY DNA STRAND?EXAMPLE 13’ end 5’ end

ATTGACCATTGATAGCCGAATATAACTGGTAACTATCGGCTTAT

EXAMPLE 25’ end 3’ end

TCTTCGGAACATTAGTCGAGGCAGAAGCCTTGTAATCAGCTCCG

Now you try!

Find the complementary DNA strand!

1. TAG ACC CAG CCC

2. CCG CAC CTG TTA AAA