DNA, Replication and Transcription Bob Jesberg NSTA Conference Boston, MA April 3, 2014 1
Workshop Agenda Looking at DNA and Forensics The DNA, Replication i and Transcription i Set DNA Ladder The Double Helix and Replication Transcription, Translation and Mutation Forensics Challenge 2
The DNA, Replication and Transcription Set 521 K NEX Pieces Builds 19 color coded models Supports a team of 2 3 students Models DNA and mrna Models can be in the form of ladders, on stands or with a flexible central core. 3
The Teacher Guide DNA Structure Building the DNA Ladder Forming the Double Helix Structure Replication and Transcription The Basic Replication Process mrna Production Coding,Translation, and Mutations Coding Glucagon: A Small Protein Translation of a mrna Transcript DNA Mutations 4
Key Concepts Molecular Basis of Heredity Transcription and mrna Production Chemistry of DNA DNA Structure The Double Hli Helix Enzymatic Control of DNA Processes Semi Conservative Replication of DNA Translation of the DNA Code Deletion, Substitution, and Insertion Mutations Nuclear and Cytoplasmic Processes of DNA 5
NSES Science Content Standards Unifying Concepts and Processes Evidence, models and explanation Science as Inquiry Abilities necessary to do scientific inquiry Understanding about scientific inquiry Life Science Grade 5 8 Grade 9 12 Structure and function of living systems Molecular basis of heredity Reproduction and heredity Biological evolution Diversity and adaptations of organisms Science and Technology Understanding about science and technology 6
Next Generation Science Standards Develop and use a model to describe why structural changes to genes (mutations) located on chromosomes may affect proteins and may result in harmful, beneficial, or neutral effects to the structure and function of the organism. Construct an explanation based on evidence for how the structure of DNA determines the structure of proteins which carry out the essential functions of life through systems of specialized cells. Ask questions to clarify relationships about the role of DNA and chromosomes in coding the instructions for characteristic traits passed from parents to offspring. Make and defend a claim based on evidence that inheritable genetic variations may result from: (1) new genetic combinations through meiosis, (2) viable errors occurring during replication, and/or (3) mutations caused by environmental factors.
Building the DNA Ladder Refer to pages 2 3 in the Instructions Booklet. Each of the pieces in the set is color coded to represent the various chemical components of DNA. Turn to pages 4 5 to construct a DNA ladder. The chart at the bottom of the page indicates the nucleotides you will need for this activity. 8
Twisting the DNA Ladder to form a Helical Molecule! Your challenge is to twist the ladder to form a double helix and mount it on a display stand. Refer to pages 6 and 7 in your instruction booklet. Keep in mind that DNA is a right handed molecule. 9
Replicating DNA The replication process provides the cell with two exact copies of an original DNA molecule. The original DNA is the parent molecule and the newly formed DNA are the daughter molecules. 10
Transcription The model of mrna shown on the left carries the code from a DNA template strand. If you refer to pages 18 and 19 of the instruction booklet, you will see how the model dlis formed and the code transcribed. 11
Translation and Mutations You can place the mrna transcripts on large sheets of paper to translate the mrna. You can bracket the codons and use a key from the Teacher Guide to determine the appropriate amino acid sequence. Mutation activities in the teacher guide demonstrate how the amino acid sequencechangeswhenaninsertion changes insertion, deletion, orsubstitutionmutation occurs. Each of these mutation scenarios can be modeled with the materials in the DNA, Replication and Transcription Set. 12
DNA and Forensics CSI type television programs have certainly brought crime scene forensics and DNA fingerprinting into vogue with students! How do we tap that growing interest to help students better understand the science behind the TV screen? DNA models that can be coded to any nucleotide sequence can provide endless opportunities for teachers to simulate molecular level crime scene investigations and provide materials for further investigation of DNA and mrna. 13
Let s get down to work! Each group has been provided with a DNA sample from a crime suspect. Our first task is to list the sequence of nucleotides found on your molecules. Refer to page three in your Instruction Booklet to determine the color codes used for the various nucleotides. There are two standard conventions we can use to transfer the sequence to paper. 14
Representing Your Molecule on Paper! GCCAGATCATTT CGGTCTAGTAAA OR 5 GCCAGATCATTT 3 3 CGGTCTAGTAAA 5 15
Finding your Molecule I am going to collect all of the DNA molecules and place them on the floor. Your task is to review the molecules on the floor and determine which one is yours. 16
Forensics Challenge Follow the directions given and see if your group can identify the subject. 17
Forensics Activity Summary Participants had to use a variety of science skills to identify the DNA match. Observation Analysis Record keeping Data collection Critical thinking Logical thinking The activity it can serve as a spring board dto further research related ltdto DNA fingerprinting, crime scene science, polymerase chain reaction, and forensic investigational techniques. 18