1. CHAPTER 13 RNA & Protein Synthesis

2. GENE EXPRESSION  When a cell “reads” the DNA, it doesn’t directly say for example blue eyes.  What the DNA actually says is what types of proteins to make, when to make them, & how much of them to make.  This is what we term gene expression.  Expressing the genetic information by using the DNA code to create a protein that does a specific job or controls a specific trait.

3. GENE Not all your DNA actually codes for something. Some of your DNA is junk DNA. Scientists are still not sure what all of your DNA does. However, a gene is a specific segment of DNA that does code for something.  It codes for a protein! Each chromosome contains many genes  controls many proteins - traits

4. WHAT IS A PROTEIN? Made up of the elements: C, H, O, N Chain of amino acids – polypeptide Function as enzymes (control reactions), messengers, structural components (muscles) About 20 different amino acids (differ by their r/variable group) The particular sequence or pattern of amino acids in the chain makes one protein different from another.

5. PROTEIN STRUCTURE

6. DNA TO A PROTEIN The sequence or pattern of these amino acids that make up a protein are coded for in your DNA. This is one of the ways that you DNA is the instructions that make you = you. But what happens if there is a change or mutation to the DNA? If the DNA gets change then you do not make the right protein, which means whatever job that protein was suppose to do doesn’t get done. Many genetic disorders are due to such mutations.

7. OVERALL ORDER DNA  mRNA  Protein

8. PROTEIN SYNTHESIS 2 stages 2 stages Transcription  Translation (nucleus) (ribosome) Convert DNA into mRNA Convert mRNA into a protein

9. DNA VS. RNA DNA Double Stranded not Does not leave the nucleus A T C G Sugar - Deoxyribose RNA Single Stranded Can leave the nucleus (pores) A U C G Sugar – Ribose 3 Types

10. TYPES OF RNA  mRNA – messenger RNA  carries the message of how to make a protein from the nucleus to the ribosome  determines the order of amino acids in a protein  contains the codon (group of 3 “letters” on the mRNA)  rRNA – ribosomal RNA (makes up the ribosome)  tRNA – transfer RNA  carries or transports the amino acids needed to make the protine to the ribosome  contains the anticodon

11. TRANSCRIPTION Purpose: convert DNA into mRNA Location: Nucleus 3 Steps:3 Steps: 1.Initiation 2.Elongation 3.Termination Enzyme: RNA Polymerase

12. PRACTICING TRANSCRIPTION Let’s say this is our DNA  TACATTCGGATC What would our mRNA look like? Use the rules of base pairing! Except now A – U, C – G

13. PRACTICING TRANSCRIPTION DNA  TACATTCGGATC mRNA  AUGUAAGCCUAG

14. TRANSLATION Purpose: convert mRNA into a protein Location: Ribosome 3 Steps: 1.Initiation a.Begins when the ribosome reaches the start codon (3 letters on mRNA usually AUG) 2.Elongation a.Protein gets bigger by adding more amino acids. 3.Termination a.Ribosome reaches a stop codon. (UAA, UAG, or UGA)

15. TRANSLATION – DRAW A PICTURE!

16. TRANSLATION