DNA and the Structure of Proteins Section a: What is DNA? National 5 Biology DNA and the Structure of Proteins Section a: What is DNA?

Recap On white boards write down what you can remember from S1-S4 or your own general knowledge about genetics and inheritance

What are we learning today? We are learning to: State what DNA is Describe the structure of DNA The purpose of DNA Success Criteria: Double helix Number of bases Names of bases Genetic code

What is DNA? DNA clip What is DNA?

What is DNA? DNA stands for Deoxyribonucleic acid DNA is found in a cells nucleus DNA is packaged in chromosomes Chromosomes have areas on them that code for protein – these areas are called genes

What is the structure of DNA? Double stranded (double helix) Sugar phosphate backbone 4 bases Adenine – A Thymine – T Guanine – G Cytosine - C

Sugar phosphate backbone

4 bases Adenine – A Thymine – T Cytosine - C Guanine – G

The 4 Bases The 4 bases bond in a complimentary way Adenine always with thymine (A-T) Guanine always with cytosine (G-C)

Activity Build your own molecule of DNA Follow the instructions carefully For Teachers - Origami DNA video instructions If time you may get the opportunity to play the pairing game DNA - The Double Helix