How DNA Makes You Part 1: Transcription Gene to Protein How DNA Makes You Part 1: Transcription

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

1. Copy the recipe from Grandma’s secret recipe file. Location of recipe: Grandma’s house Product: Instructions to make the best cookies in Hoboken NJ (words)

Grandma lives in a retirement home, so she doesn’t cook. 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 ingredients in correct amounts & order; bake for required time Product: Best cookies in Bucks County PA

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 traits (products) that make up each organism? What are the “products” that cause you to look and function as you?

Review: Proteins Polymers of amino acids (monomers) Structure (3-D) determines function Proteins are used for: Structure Movement Storage Defense Transport Signaling Enzymes order of amino acids determines 3-D shape Structural (hair, cytoskeleton) Movement (muscle) Storage 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  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) Brings correct amino acids to build protein Ribosomal RNA (rRNA) Helps form ribosomes: the workbench where proteins are assembled

Transcription: What Information from a single, specific gene in DNA  is copied to make mRNA (messages)

Transcription: Who DNA – Master source of information (the complete database) mRNA – Copies information to make a specific single protein (that’s why your eye cells do not make toenails!) RNA polymerase – adds nucleotides to growing mRNA

Transcription: Why Protect DNA in nucleus Information from only one gene is copied by each mRNA to produce a specific protein

Transcription: Where Nucleus of cell

Transcription: How Step by step (lew-Port – complete; view the first section for transcription)

Overview - tutorial Initiation – begin at promoter* Elongation – add nucleotides to growing mRNA Termination – stop copying at end of gene Transcription begins at the promoter, proceeds through the coding region, and ends at the terminator.

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 “processed” before leaving nucleus

Transcription: How Transcription Complete RNA synthesis involves separation of the DNA strands and synthesis of an RNA molecule in the 5' to 3' direction by RNA polymerase, using one of the DNA strands as a template. RNA polymerase catalyzes a chemical reaction resulting in the synthesis of RNA on a DNA template strand. Transcription begins at the promoter, proceeds through the coding region, and ends at the terminator. Transcription Complete

Transcription: The Product mRNA copy of DNA information to make protein Processed (remove introns) mRNA leaves the nucleus mRNA 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)

Links for more information: Lew-Port Protein Synthesis RNA is very similar to DNA Transcription overview (biocoach) Transcription Process (biocoach) Transcription complete (biocoach)