Bio 9C: Thursday, Title: RNA Structure and Function  Homework:  Read pages in the textbook. Take active reading notes, paying attention to important vocabulary terms and to the following purpose questions: How does the genetic code work? What are the steps of translation? Do Now:  Today’s Objectives:  Describe the major structural differences between DNA and RNA  Differentiate between structure and function differences between the types of RNA

RNA: STRUCTURES & FUNCTIONS PHA Biology 9 Moretti and Dickson

RNA Structure & Function of Different Types

RNA Structure: Base Pairing  4 Nitrogen Bases in RNA:  Adenine  Guanine  Uracil  Cytosine  RNA –> DNA Base Pairing:  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

RNA Structure: DNA vs. RNA 3 Major Structural Differences DNARNA Deoxyribose SugarRibose Sugar Double Strand Single Strand (generally) Uses Thymine (T)Uses Uracil (U) Objectives for Class: Describe the major structural differences between DNA and RNA Differentiate between structure and function differences between the types of RNA

Types of RNA: Overview Type of RNABasic Function Messenger RNA (mRNA) Copy genes on the DNA (transcription) Transfer RNA (tRNA) Translate mRNA into a protein Carry amino acid to the ribosome Ribosomal RNA (rRNA) (we will not focus on rRNA) Part of the ribosome Objectives for Class: Describe the major structural differences between DNA and RNA Differentiate between structure and function differences between the types of RNA

 Basic Structure:  Single Strand of RNA  Basic Function  Make a copy of DNA instructions to make a protein  Takes those instructions from DNA to Ribosome to make a protein  Every 3 bases is a Codon Remember: Small enough to leave the nucleus. DNA is too big! Types of RNA: Messenger RNA (mRNA) Objectives for Class: Describe the major structural differences between DNA and RNA Differentiate between structure and function differences between the types of RNA

 Basic Structure:  Coiled RNA strand  Amino Acid attached to the top  Anti-codon on the bottom  Basic Function:  Transfer amino acids to the ribosome to make a protein  Anti-codon on tRNA matches/ reads codon on mRNA Types of RNA: Transfer RNA (tRNA) Objectives for Class: Describe the major structural differences between DNA and RNA Differentiate between structure and function differences between the types of RNA

Types of RNA: Transfer RNA (tRNA) Objectives for Class: Describe the major structural differences between DNA and RNA Differentiate between structure and function differences between the types of RNA

Decoding the Genetic Code

The Genetic Code  The 64 Codons that code for Amino Acids Objectives for Class: Use the genetic code to translate a DNA or RNA sequence into an amino acid sequence to make a protein.

Reading The Genetic Code  mRNA codons are 3 bases long and specify a particular amino acid.  To use the wheel, the 1 st base (letter) of codon matches the biggest letter and you move out from the middle to read the rest of the codon.  Therefore, the 2 nd base in the codon is the second biggest letter (the one in the middle ring) and the 3 rd base In the codon is the smallest letter (the one in the outer ring).  The arrows show the direction you should read it.

The Genetic Code  Complete Part I of the “Decoding the Genetic Code!” Activity. (we will review the first 3 examples of question 1 after you have had a chance to complete them) Objectives for Class: Use the genetic code to translate a DNA or RNA sequence into an amino acid sequence to make a protein.

Reading The Genetic Code: Examples Follow along with the examples in your packet! Example 1: CAG  1 st base = C  2 nd base = A  3 rd base = G Therefore the amino acid is…  Glutamine! Example 2: GUU  Valine

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 2 3

Bio 9C: Friday, Title: Transcription and Translation with RNA  Homework:  No Homework over the break!  Do Now: In your notebook:  If you had a DNA sequence of T A C A G C T, what would the matching RNA sequence be?  Hit the space bar to see the answer… A U G U C G A  Today’s Objectives:  Demonstrate your understanding of DNA, the Cell Cycle and Mitosis

MCAS Prep Question The mold Aspergillus flavus grows on grain. A. flavus produces a toxin that binds to DNA in the bodies of animals that eat the grain. The binding of the toxin to DNA blocks transcription, so it directly interferes with the ability of an animal cell to do which of the following? A. Produce ATP using energy released from glucose and other nutrient B. transport glucose across the cell membrane into the cytoplasm C. Transfer proteins from the endoplasmic reticulum to Golgi complexes D. Send protein-building instructions from the nucleus to the cytoplasm and ribosomes

 Overview:  What is the hidden message in Part II of the homework assignment?  “Give Neighbor High 5” Homework Review Question Objectives for Class: Describe the purpose and major steps of transcription Describe the purpose and major steps of translation

 Overview:  A DNA gene is copied in the form of mRNA  Occurs in the nucleus  Steps: 1. RNA Polymerase separates DNA strands 2. RNA Polymerase moves along one of the DNA strands (template) 3. RNA Polymerase makes mRNA by attaching RNA nucleotides that match the DNA template mRNA Transcription Detail Objectives for Class: Describe the purpose and explain the major steps of transcription.

Types of RNA: Messenger RNA (mRNA) mRNA (the orange strand) DNA (the red & green strands) Objectives for Class: Describe the major structural differences between DNA and RNA Differentiate between structure and function differences between the types of RNA

tRNAtRNA mRNA tRNAtRNA Ribosome Codons & AntiCodons  Codon  3 base sequence on mRNA that specifies a single amino acid to be added to the polypeptide (protein)  Anticodon  3 base sequence on tRNA that are match up with the mRNA codon Objectives for Class: Describe Polypeptide Anticodon Codon Amino Acid

Translation Detail  Overview:  mRNA copy provides instructions for assembling amino acids into a protein  Occurs at the ribosome  Steps: 1. mRNA enters the ribosome 2. tRNA molecules bring amino acids to the ribosome 3. tRNA anticodons match with mRNA codons to put amino acids in the right order According to the Genetic Code Objectives for Class: Describe the purpose and major steps of transcription Describe the purpose and major steps of translation

Translation Objectives for Class: Describe the purpose and major steps of transcription Describe the purpose and major steps of translation

Transcription & Translation TranscriptionTranslation Objectives for Class: Describe the purpose and major steps of transcription Describe the purpose and major steps of translation

Transcription and Translation: Video Objectives for Class: Describe the purpose and major steps of transcription Describe the purpose and major steps of translation  Transcription and Translation Video: 17_13ProteinSynthesis.mpg 17_13ProteinSynthesis.mpg

Bio 9C: Monday, Title: Transcribe and Translate a Gene Computer Lab  Homework:  Pass in the codons and amino acid decoding practice homework  Complete Part II of the Transcription & Translation Computer Lab  Do Now:  Sign into a computer and turn around with your back to the computers to wait for your next instructions.  Today’s Objective:  Use the steps of transcription and translation to turn a section of DNA into a protein.

Transcribe and Translate a Gene Computer Lab TranscriptionTranslation Objectives for Class: Use the steps of transcription and translation to turn a section of DNA into a protein. Procedure:  Log onto  Scroll down to the middle of the homepage and click on the link entitled “Are you ready to transcribe a DNA sequence and translate it into a protein?”  A DNA sequence should appear on the screen. Transcribe the DNA strand by entering the corresponding RNA bases for the original strand. The new mRNA strand will now appear on the screen.  Locate the “start” codon and click on it with your mouse. The mRNA sequence will now move to the top of the field and a flashing box will appear around the “start” codon.  Using the “Universal Genetic Code” to the right, find the amino acid that corresponds with the three-base mRNA codon. Click on the appropriate amino acid and drag it to the corresponding mRNA codon (signaled by the flashing box). Repeat until the mRNA sequence has been Translated.  Answer the Review and Analysis questions for Part I as you complete the lab.  Answer the Review and Analysis questions for Part II after the computer portion of the lab is completed.

Remember R-groups?