I can… Agenda Index Card Question HW Review Translation Notes Stick People Lab Codon Bingo Mutations Notes QuizIzz Homework: Transcription & Translation Worksheet Describe the process of translation Explain the steps of the central dogma of biology Translate codons to Amino Acids Discuss the various types of mutations and their effects 

Translation and Proteins

Protein Review What are the monomers of proteins? How many different Amino Acids are there? What are the three parts of an Amino Acid? Amino Acid 20 Amine Group Carboxyl Group R Group

Translation mRNA is translated into a protein (polypeptide), or a string of amino acids held together by peptide bonds Purpose: to make proteins Location: Cytoplasm

Codon Any three consecutive nucleotides on mRNA CODES for an amino acid. AUG= Start/Methionine UAA, UGA or UAG= Stop Anticodon: complementary codon on tRNA

Translation - Initiation Image 1 of 4 Draw This image Box #1 The ribosome binds to the mRNA cap and moves down the mRNA until the start codon (AUG) reaches the ribosome’s P site Next the first tRNA (with the anti-codon UAC) will bind to the ribosome

Translation - Elongation Image 2 of 4 met Peptide bond Met= methionine Draw This image Box #2 A new tRNA molecule attaches to the ribosome in the A site. This tRNA will pair with the next codon of mRNA. The ribosome will form a peptide bond between the amino acids attached to the first two tRNAs.

Translation - Elongation Image 3 of 4 To be recharged Draw This image Box #3 Once the bond is formed the ribosome will move over causing the tRNA to enter the ribosome’s E side and exit the ribosome.

Protein Synthesis

Translation - Termination Image 4 of 4 Draw this image Box 4 AGC The ribosome will continue to move down the mRNA, adding amino acids to the growing string of amino acids until it reaches the stop codon. No tRNA bonds to the ribosome and translation is over! The complex will come apart.

Translation - Termination Image 4 of 4 AGC Draw This image Box #4 The ribosome will continue to move down the mRNA, adding amino acids to the growing string of amino acids until it reaches the stop codon. No tRNA bonds to the ribosome and translation is over! The complex will come apart.

Translation Mechanism MET This process continues until a stop codon is reached, at which point the mRNA strand, tRNA units, and rRNA subunits are all released. MET ISO PRO A U G C tRNA U A U tRNA U A C tRNA U A C tRNA U A U tRNA G G G Start Codon (Methionine) Large Ribosomal Subunit (rRNA) E Site A Site P Site mRNA A U G C Small Ribosomal Subunit (rRNA)

I can… Agenda Index Card Question HW Review Translation Notes Stick People Lab Codon Bingo Mutations Notes QuizIzz Describe the process of translation Explain the steps of the central dogma of biology Translate codons to Amino Acids Discuss the various types of mutations and their effects 

Mutations Mutations can happen in two locations: Sex cells: affect the offspring Body cells: affect the individual only Mutations can have one of three affects: Those that cause a disease Those that are beneficial Silent mutations: do not cause disease – most common Mutations can be one of two types: Point mutations: affecting single nucleotide Chromosomal mutations: affect section of or whole chromosome

Causes of Mutations Mistakes in base paring during DNA Replication DNA Polymerase can usually detect such errors When missed, may cause many genetic disorders Chemicals: like tobacco Can lead to cancer because it changes the genes that regulate mitosis Radiation: including UV (sun) and X-ray

Point Mutations 1. Substitution One nitrogen base is substituted for another Sickle Cell Anemia: substitute A for T

Point Mutations 2. Deletions and insertions When a nitrogen base is deleted or added Causes a Frame shift mutations- because it moves the codon up or down Changes the sequence of amino acids

Mutation Expression Silent: no change in original sequence of proteins. May occur from change in base that does not change codon, or to a codon that codes for the same Amino Acid

Missense: change in one DNA base pair that results in the substitution of one amino acid for another

Nonsense: change in on DNA base pair that results in premature stop codon Rather than coding for an Amino Acid, the stop codon ends the production of the polypeptide chain Results in a shortened protein that may function improperly or not at all. Most severe outcome.