Gene Expression: Using DNA to make proteins

1. Gene Expression:Using DNA to make proteins PHA Biology 9

2. A Day in the Life of The Cell Released into blood stream and used as hormone or other bodily structure Golgi Apparatus (Modifies and shapes the protein) Ribosome Protein being formed at Ribosome Protein Nucleus Cytoplasm Protein could go to membrane to be released into blood stream RNA Vesicles (“bubbles” that transport proteins) E.R. (transports and packages proteins) Cell Membrane RNA ::Blood Stream:: DNA Ribosomes (Stores genetic information) (Copies genetic from DNA and carries it to the Ribosome to make proteins)

3. Overview: Using DNA to Make Proteins [Turn your notebook sideways and write this in big letters in the middle of the page – take up the whole length of the page! Leave plenty of space above and below it.] DNA RNA Protein Trait • Stays in the nucleus • Copies itself and gets passed on to new cells • Holds instructions for making proteins • Observable characteristic • “Who you are” • Made in the nucleus and goes to the cytoplasm • Uses DNA instructions to make proteins • Used as body structures (muscle, bone, skin, hair), enzymes, transporters, hormones, etc.

5. DNA RNA Protein Trait Overview: Using DNA to Make Proteins Transcription: The process of making RNA by copying DNA Translation: The process of using info in RNA to make proteins • Stays in the nucleus • Copies itself and gets passed on to new cells • Holds instructions for making proteins • Observable characteristic • “Who you are” • Made in the nucleus and goes to the cytoplasm • Uses DNA instructions to make proteins • Used as body structures (muscle, bone, skin, hair), enzymes, transporters, hormones, etc.

6. Differences between DNA and RNA DNA RNA • Deoxyribose sugar • Double strand (forms a helix) • Bases: A, T, G, C • Ribose sugar • Single strand (can form different shapes) • U instead of T (A, U, G, C) • Objectives for Class: • Describe the major structural differences between DNA and RNA • Differentiate between structure and function differences between the types of RNA

7. Base Pairing between DNA and RNA DNARNA A ------ U T ------ A C------ G G ------ C • Objectives for Class: • Describe the major structural differences between DNA and RNA • Differentiate between structure and function differences between the types of RNA

8. Transcription: Copying DNA into RNA DNA (the red & green strands) mRNA (the orange strand) • Objectives for Class: • Describe the major structural differences between DNA and RNA • Differentiate between structure and function differences between the types of RNA

9. Transcription • Overview: • A DNA gene is copied into RNA • Occurs in the nucleus • Steps: • RNA Polymerase separates (unzips) DNA strands • RNA Polymerase makes RNA by matching complementary nucleotides with the DNA strand • mRNA leaves nucleus and DNA winds back up! • Final Result: mRNA copy of a gene • Objectives for Class: • Describe • Objectives for Class: • Describe the purpose and major steps of transcription • Describe the purpose and major steps of translation mRNA

10. Three Types of RNA: • Messenger RNA (mRNA) - Carries a copy of protein-making instructions to the ribosome • Codon = 3 letters on mRNA that stand for one amino acid • Transfer RNA (tRNA) – Carries amino acids to the ribosome • Contains anticodonsthat match up with mRNA codons to put amino acids in the correct order • Ribosomal RNA (rRNA) – Part of the ribosome (helps bond amino acids together)

11. Transfer RNA (tRNA) Structure (Draw it!) • Amino Acid attached to the top • Anti-codon on the bottom • Objectives for Class: • Describe the major structural differences between DNA and RNA • Differentiate between structure and function differences between the types of RNA

12. Ribosomal RNA (rRNA) • Acts like an enzyme to bond amino acids together into long chains (proteins!)

13. Translation Details • Overview: • The gene sequence in mRNA is translated into a chain of amino acids that forms a protein • Occurs at the ribosome • Steps: • mRNA enters the ribosome • tRNA molecules bring amino acids to the ribosome • tRNAanticodons match with mRNA codons to put amino acids in the right order • According to the Genetic Code • Ribosome connects the amino acids into a long chain • Final Result: A polypeptide (protein)

14. Making Proteins at the Ribosome Amino Acid Growing Protein t RNA t RNA Ribosome Anticodon Codon mRNA • Objectives for Class: • Describe • Objectives for Class: • Describe the purpose and major steps of transcription • Describe the purpose and major steps of translation

15. Translation Ribosome Growing protein chain mRNA strand • Objectives for Class: • Describe • Objectives for Class: • Describe the purpose and major steps of transcription • Describe the purpose and major steps of translation

16. Transcription & Translation Transcription Translation • Objectives for Class: • Describe

17. Reading The Genetic Code • The letters in the wheel are mRNA codons • Start in the middle! • This is the first letter in the codon • Move to the middle ring (2nd letter in the codon) • Then go to the outer ring of letters (3rd letter in the codon) • Outermost ring = amino acids!

18. Reading The Genetic Code: Examples • Follow along with the examples on your worksheet! • Example 1: CAG • 1st base = C • 2nd base = A • 3rd base = G • Therefore the • amino acid is… • Glutamine! • Example 2: GUU • Valine

19. Reading The Genetic Code: Longer Example • Example 3: GCCAGCUAG • Step 1: Break it into 3-letter sections (codons) • GCC AGC UAG • Step 2: Decode each codon • GCC = Alanine • AGC = Serine • UAG = STOP(end of protein sequence) 1 3 2

20. Gene Mutations Activity: Part I Review • What is a Genetic Mutation? • A change in the base-pair sequence of DNA • The three types of point mutations: • substitution (switch one DNA nucleotide for another) • insertion (add an extra nucleotide into the DNA sequence) • deletion (leave out one nucleotide in the DNA sequence) • Objectives for Class: • Describe the major differences between substitution and frame-shift mutations

21. Genetic Mutations Activity – Substitution Mutations • Original DNA Sequence • Substitution Changes the Amino Acid • Substitution/ Silent Mutation Does not Change the Amino Acid • Objectives for Class: • Describe the major differences between substitution and frame-shift mutations

22. Genetic Mutations Activity –Frame-Shift Mutations • Frame-Shift Mutations • Original DNA Sequence • Frame-Shift: Deletion of nucleotide Changes all Amino Acid after mutation • Frame-Shift: Insertion/ Addition of nucleotide Changes all Amino Acid after mutation • Objectives for Class: • Describe the major differences between substitution and frame-shift mutations

23. Lab: Sickle Cell and Genetic Mutations

24. Lab: Sickle Cell and Genetic Mutations

25. Valine: • Glutamic acid: