RNA: STRUCTURES & FUNCTIONS

PHA Biology 9Moretti and Dickson

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

DNA RNADeoxyribose Sugar Ribose 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: OverviewType of RNA Basic Function

Messenger RNA (mRNA)

Copy genes on the DNA (transcription)

Transfer RNA (tRNA)

Translate mRNA into a proteinCarry 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

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

Bio 9B: Friday, 2.25.10Title: Sub-Plan - Cell Regulation, Cancer & Stem Cells

Homework: Read pages 302-306 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: Take out your notebooks and have one student from each table

get enough Biology books for all students at the table.

Today’s Objectives: Explain how cells regulate their growth and division Explain how the cell cycle and mitosis relates to cancerous cells. Describe what stem cells are and how they may be useful to medicine. Explain some of the controversial issues surrounding stem cells.

Bio 9B Sub-Plans for Friday, 2.25.10

Today’s Plan: Part I: Actively Read Section 10-3 (pages 250-253), including

the page on Stem Cells. Take reading notes in your notebooks. Part II: Answer the following questions on a separate piece

of paper to be handed in: What is cancer, and how does it relate to the cell cycle? Use the info on pages 250-251 to think of a drug that might help

prevent or stop cancer. Explain how your new drug would work. What are stem cells? Why are they important in the human body? What are some possible medical uses of stem cells? Be specific Why are stem cells controversial? Do you think scientists should be

allowed to work with stem cells? Explain!

These are INDIVIDUAL Assignments!!!!

Bio 9B: Monday, 3.1.10Title: Transcription w/ RNA and the Genetic Code

Homework: Complete Part II (page 2) of the Decoding DNA

Do Now: MCAS Prep Do Now on following page

Today’s Objectives: Differentiate between structure and function

differences between the types of RNA Use the genetic code to translate a DNA or RNA

sequence into an amino acid sequence to make a protein.

Do Now: MCAS Prep

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 ribosomesObjectives for Class:

• Describe the purpose and major steps of transcription

Types of RNA: Review and Refresher

Type of RNA Basic Function

Messenger RNA (mRNA)

Copy genes on the DNA (transcription)

Transfer RNA (tRNA)

Translate mRNA into a proteinCarry 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: 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

t RNA

mRNA

t RNA

Ribosom

e

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 matches up with the mRNA codon

Objectives for Class:• Describe

Polypeptide

Anticodon

Codon

Amino Acid

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 1st base (letter) of codon matches the biggest letter and you move out from the middle to read the rest of the codon.

Therefore, the 2nd base in the codon is the second biggest letter (the one in the middle ring) and the 3rd 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: ExamplesFollow along with the

examples in your packet!

Example 1: CAG

1st base = C 2nd base = A 3rd base = G

Therefore theamino acid is…

Glutamine!

Example 2: GUU

Valine

Reading The Genetic Code: Longer ExampleExample 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 9B: Tuesday, 3.2.10Title: Transcription and Translation Details

Homework: Take out last night’s homework and get ready to hand it in

(but not until I say so, after the Do Now More codon and amino acid decoding practice

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? A U G U C G A

Today’s Objective: Describe the purpose and major steps of transcription Describe the purpose and major steps of translation

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 strands2. RNA Polymerase moves along

one of the DNA strands (template)

3. RNA Polymerase makes mRNA by attaching RNA nucleotides that match the DNA template mRN

A

Transcription Detail

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

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

Translation Detail Overview:

mRNA copy provides instructions for assembling amino acids into a protein

Occurs at the ribosome

Steps: 1. mRNA enters the ribosome2. 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 CodeObjectives for Class:• Describe the purpose and major steps of transcription• Describe the purpose and major steps of translation

Transcription & Translation

Transcription

TranslationObjectives 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 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

Bio 9B: Thursday, 3.4.10Title: Transcribe and Translate a Gene Computer Lab

Homework: Pass in the codons and amino acid decoding practice

homework Complete Part I of the Genetic Mutations Activity

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.

Double Block

Transcribe and Translate a Gene Computer Lab

Transcription

Translation

Objectives for Class:• Use the steps of transcription and translation to turn a section of DNA into a protein.

Procedure: Log onto

http://gslc.genetics.utah.edu/units/basics/transcribe/ 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?

Bio 9B: Friday, 3.5.10Title: Genetic Mutations Day 1 – Types of Mutations

Homework: Complete Part II of the Genetic Mutations Activity For

Monday Quiz next TUESDAY!

Do Now: How was your description of a genetic mutation

similar to what a mutation actually is?

Today’s Objective: Describe the major differences between

substitution and frame-shift mutations

Gene Mutations Activity Part I Review

What is a Genetic Mutation? A change in the base-pair sequence of DNA

The three types of point mutations: substitution (switch one DNA nucleotide for

another) insertion (add an extra nucleotide into the

DNA sequence) deletion (leave out one nucleotide in the

DNA sequence)

Objectives for Class:• Describe the major differences between substitution and frame-shift mutations

Gene Mutations Activity Part II Complete Part II of the Gene Mutations Activity by comparing

substitution & frame-shift mutations Part II Review:

Original DNA Sequence

Objectives for Class:• Describe the major differences between substitution and frame-shift mutations

Gene Mutations Activity Part II Substitution Mutations

Original DNA Sequence

Substitution

Substitution/ Silent Mutation

Changes the Amino Acid

Does not Change the Amino AcidObjectives for Class:• Describe the major differences between substitution and frame-shift mutations

Gene Mutations Activity Part II Frame-Shift Mutations

Original DNA Sequence

Frame-Shift: Deletion of nucleotide

Frame-Shift: Insertion/ Addition of nucleotide

Changes all Amino Acid after mutation

Changes all Amino Acid after mutation

Objectives for Class:• Describe the major differences between substitution and frame-shift mutations

Bio 9B: Monday, 3.8.10Title: Genetic Mutations Day 2 – Sickle Cell Case Study

Homework: Study for Quiz Tomorrow!!! Type the Background Information section of your lab report for

Thursday. (NOTE: completed lab reports are due Friday at the start of class. You will have time to work on it during Thursday’s class, but if you need more time/ don’t have access to a computer at home, please make arrangements now to complete the lab Thursday after school)

Do Now: H

Today’s Objective: Brainstorm and organize the background information

necessary to successfully explain what sickle cell anemia is and how it is caused.

Lab: Sickle Cell and Genetic Mutations

A Case Study of Sickle Cell Disorder Read through the Introduction to the lab. Watch 5 minute video on sickle cell disorder

PBS Evolution Library: A Mutation Story http://www.pbs.org/wgbh/evolution/library/01/2/l_012_02.

html In small groups brainstorm the Background

Information needed for this lab You should have 2 parts:

1. General genetics background info2. Info related to sickle cell anemia

Come back together as a class to brainstorm final listObjectives for Class:

• Brainstorm and organize the background information necessary to successfully explain what sickle cell anemia is and how it is caused.

Lab: Sickle Cell and Genetic Mutations

Background Information BrainstormGenetics Topics: •

Sickle Cell Topics:•

Bio 9B: Tuesday, 3.9.10Title: Quiz – Transcription, Translation, and Mutations

Homework: Type the Background Information section of your lab report for

Thursday. (NOTE: completed lab reports are due Friday at the start of class. You will have time to work on it during Thursday’s class, but if you need more time/ don’t have access to a computer at home, please make arrangements now to complete the lab Thursday after school)

Do Now: Clear your desks and get ready to take the quiz…

Today’s Objective: Demonstrate your understanding of how the processes of

transcription and translation create proteins from the genetic code on DNA

Bio 9B: Thursday, 3.11.10Title: Genetic Mutations Day 3 – Sickle Cell Case Study

Homework: Complete the Procedure, Analysis and Conclusion

sections of your lab report. Completed lab report with all sections is due tomorrow, Friday, at the start of class!!!!

Do Now:

Today’s Objective: Analyze the DNA sequence for the sickle cell gene

and the normal gene to determine how DNA is mutated to result in sickle cell anemia

Complete the Sickle Cell Mutation Lab Report

A Case Study of Sickle Cell Disorder Analyze the DNA sequence for the sickle cell

gene and the normal gene by transcribing and translating them.

Compare the sickle cell gene to the normal gene

Complete the analysis and conclusion sections of the lab report.

Objectives for Class:• Analyze the DNA sequence for the sickle cell gene and the normal gene to determine how

DNA is mutated to result in sickle cell anemia• Complete the Sickle Cell Mutation Lab Report

Lab: Sickle Cell and Genetic MutationsFirst Half of Double Block

Individual Work Time… Two Options:

1. Type Analysis and Conclusion sections of lab report and revise your other sections

2. Guided peer review of Background Information section

Lab: Sickle Cell and Genetic MutationsSecond Half of Double

Block

Objectives for Class:• Analyze the DNA sequence for the sickle cell gene and the normal gene to determine how

DNA is mutated to result in sickle cell anemia• Complete the Sickle Cell Mutation Lab Report