Do Now: Write the questions and answer them on page ___. What are the three types of RNA? Why does the DNA have to be turned into RNA? What base is used instead of thymine in RNA?

Objectives SWBAT explain the basic processes of transcription and translation. SWBAT explain how both transcription and translation result in the expression of genes. SWBAT explain how mutations may or may not result in a phenotypic change.

Why is the sequence of nucleotides in DNA molecules so important? Essential Question Why is the sequence of nucleotides in DNA molecules so important?

Key Point #1 Translation turns mRNA into a Protein, the building blocks of organisms

Last class we used Transcription to turn DNA RNA. Today, we are going use Translation to turn RNA Protein.

What does it mean to translate something?

Triplet Code: How Genes Are Read Common Language: The same genetic code is shared by almost all organisms All genetic code is made of Adenine (A), Thymine (T), Cytosine (C), and Guanine (G)

Triplet Code: How Genes Are Read Start Codon: signals the start of translation Codon: 3-nucleotide sequence that codes for the amino acid Stop Codon: signals the end of building the amino acid chain

3-nucleotide sequence that codes for an amino acid Anticodon 3-nucleotide sequence that codes for an amino acid

Where does protein synthesis and translation occur? Inside the Ribosomes!

Process: Translation After transcription, mRNA leaves the nucleus and attaches to the ribosome at the start codon where translation begins. Translation: mRNA is turned into amino acids which fold to make proteins. Translation

Process: Translation 2) The mRNA is “read” in sets of three nucleotides (codon) which code for different amino acids. **The anticodon pairs with it’s codon.**

Process: Translation 3) The amino acids bond together to create an amino acid chain until the stop codon is read.

mRNA to Protein

Translation Video Questions: How is a polypeptide assembled? RNA has to bind to a ribosome What does a transfer RNA carry? When does the chain stop? Do the release factors carry amino acids?

Scientist figured out the codes for the 20 amino acids that make up proteins! We can use this chart to decode RNA. 2nd Nucleotide 1st Nucleotide 3rd Nucleotide

Check for Understanding: AUG, GGU, AND CAA, You Try: I NEED VOLUNTEERS!!!!!

Translation Practice: Write on page -Let’s practice translation! I’ll give you the mRNA strand, and you figure out what amino acids it codes for. (Remember, 3 nucleotides=1 amino acid) Use your Codon Chart in your Lab Activity Packet mRNA strand: AUG CCC UUU GAG AAG CGU UAA amino acid chain: met- pro- mRNA strand: AUG GGG UGG AGA AGU GUG UGA amino acid chain: mRNA strand: AUG AGU AAC CCA UAA

Translation Practice mRNA strand: AUG CCC UUU GAG AAG CGU UAA amino acid chain: met– pro– phen– gly– lys- arg- stop mRNA strand: AUG GGG UGG AGA AGU GUG UGA amino acid chain: met- glyc- tryp- arg - ser- val- stop mRNA strand: AUG AGU AAC CCA UAA amino acid chain: met - ser - asp - pro -stop

MUTATIONS (GENE EXPRESSIONS) What do you think caused these things to happen?

Vocabulary Genotype: collection of all organism’s genetic information that codes for traits. Phenotype: Collection of all organism’s physical characteristics.

Gene Mutations Gene Mutations: Changes in DNA that affect genetic information Point mutation: one nucleotide is substituted for another Frameshift mutation: the insertion or deletion of a nucleotide in the DNA sequence

What Causes Mutations? There are two ways in which DNA can become mutated: Mutations can be inherited. (Parent to child) Mutations can be acquired. Environmental damage (UV light, radiation such as X- rays, chemicals in food, water, air, buildings, etc). Mistakes when DNA is copied (DNA Polymerase makes mistakes about once every 100. Mistakes during crossing over - exchange of DNA between chromosomal segments.

Chromosomal Mutations Chromosomal mutations: chromosomes don’t align with each other, these segments may be different in size. Gene duplication: caused by the exchange of unequal segments during crossing over. 1 chromosome can have 2 copies of some genes and the other chromosome has no copies of those genes Translocation: movement of a piece of one chromosome to a non-homologous chromosome

Chromosomal Mutation Changes that affect part of a chromosome: Inversion Deletion Translocation

Down syndrome is caused by a third copy of chromosome 21 Potential Impacts Most mutations are neutral Examples: Eye color & Birth marks Some mutations are harmful Examples: Sickle Cell Anemia & Down Syndrome Some mutations are beneficial Examples: Sickle Cell Anemia gene provides resistance to Malaria, Immunity to HIV Down syndrome is caused by a third copy of chromosome 21

Silent Mutagen Some mutations have no apparent effect! Agents in the environment that can change DNA

Protein Synthesis Activity What is the purpose? Where can all the materials be found? Who will you be working with? How will you know you are doing it right? How long will you have?