The first step in - How DNA makes you DNA to RNA The first step in - How DNA makes you

How to Bake Grandma’s Cookies (Another Food Analogy to Help You Learn Biology)

1. Copy the recipe from Grandma’s family secret recipe file. Location of recipe - Grandma’s house Product - Written instructions to make the best cookies in Quakertown, PA

Grandma lives in a retirement home, so she doesn’t cook. You will have to copy Grandma’s recipe in order to leave Grandma’s & go to your kitchen where you will find the ingredients and utensils to make the cookies.

2. Read and follow instructions Add: correct ingredients correct amounts correct order bake for required time Product: Best cookies in town!

How is this analogous to biology? How does the information (recipe) produce the cookies (product)? How does the information in genes (sections of DNA) produce the proteins (products) that make our traits? What are the “products” that cause you to look and function as you?

Review: Proteins Polymers of amino acids (monomers) The Order of Amino Acids determines the 3D shape of a protein Structure (3-D) determines function 7 categories: Structure Movement Storage Defense Transport Signaling Enzymes order of amino acids determines 3-D shape Structural (hair, cytoskeleton) Movement (muscle) Storage (Storage proteins in seeds, milk, egg whites) Defense (antibodies, membrane proteins) Transport (hemoglobin, membrane proteins) Signaling (hormones, membrane proteins) Enzymes (catalysts for biochemical reactions)

DNA contains the “recipe” for every protein in your body Information is copied in the nucleus Copy leaves nucleus  cytoplasm Information used to assemble proteins Trait: freckles, bent pinky, floppy earlobes, curly hair

The Big Picture: 2 steps in protein synthesis 1. Transcription information from gene is copied 2. Translation Information is used to assemble amino acids into proteins  Physical Traits are determined by those proteins

DNA – Original Text of Information mRNA - Working copy of instructions

Three types of RNA: Messenger RNA (mRNA) Copies information from DNA Transfer RNA (tRNA) Transports correct amino acids to build protein Ribosomal RNA (rRNA) Helps form ribosomes: the workbench where proteins are assembled

Transcription: Why Information from a single gene is copied to make protein Need to protect DNA in nucleus

Transcription: What Information from a gene is copied to produce each protein. DNA  mRNA Protein

Transcription: Where Nucleus of cell

Transcription: How

Stop! Check Your Understanding Complete the DNA RNA chart

Initiation - Begin at Promoter region Elongation – RNA polymerase adds nucleotides through the coding region Termination – Ends at the termination sequence. mRNA is now complete

RNA polymerase DNA DNA mRNA

Transcription details Initiation: Promoter identifies region to be transcribed Elongation - Coding region has information for mRNA RNA polymerase adds nucleotides to mRNA Termination - ends transcript mRNA is “edited” before leaving nucleus

Transcription: How Transcription Complete

Transcription: What’s Next? The product is an mRNA copy of DNA information to make protein After transcription is complete: DNA – forms Hydrogen bonds and reforms double helix mRNA is edited (remove introns, exons are to be expressed) mRNA leaves the nucleus and enters cytoplasm for translation

Watch transcription in action (DNAi) click “copying the code” click putting it together click Transcription After viewing this WAY COOL movie, click interactive and make your own RNA. Transcribe a gene (DNAi)

Please summarize the process of transcription in your own words RNA polymerase transcribes a gene from DNA by adding RNA nucleotides until it reaches a termination sequence. The mRNA is edited to remove introns before leaving through a nuclear pore so that translation can happen in the cytoplasm.