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Integrating Concepts in Biology
PowerPoint Slides for Chapter 2: Central Dogma 2.3 How do cells make proteins? by A. Malcolm Campbell, Laurie J. Heyer, & Christopher Paradise Title Page Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Biology Learning Objectives
Demonstrate in writing and diagrams how proteins are made. Apply the genetic code to deduce the protein encoded by a mRNA. Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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How are Proteins Made? What is required to build a protein? Fig. 2.20
Figure 2.20 Translation produces a polymer of amino acids to form a protein. A, A peptide bond (shown as a red line) forms when two amino acids are covalently connected with water as a waste product. Colors are for illustration purposes; R1 and R2 represent additional atoms. B, In vitro translation with each column a different experiment with + indicating presence of an ingredient. Blank boxes show which ingredient was omitted. Below the table are protein gel electrophoresis results from the seven inputs above. Talking Point: Proteins are built by making new covalent bonds between individual amino acids. Fig. 2.20 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Proteins from Amino Acids
What How do cells make a new (peptide) covalent bond between two amino acids? Figure 2.20 Translation produces a polymer of amino acids to form a protein. A, A peptide bond (shown as a red line) forms when two amino acids are covalently connected with water as a waste product. Colors are for illustration purposes; R1 and R2 represent additional atoms. B, In vitro translation with each column a different experiment with + indicating presence of an ingredient. Blank boxes show which ingredient was omitted. Below the table are protein gel electrophoresis results from the seven inputs above. Talking Point: The bonds are called peptide bonds because they build proteins, also called polypeptides. This covalent bond is not different than other C-N covalent bonds. Fig. 2.20 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Proteins from Amino Acids
What ingredients: DNA energy tRNA ribosomes mRNA amino acids Figure 2.20 Translation produces a polymer of amino acids to form a protein. A, A peptide bond (shown as a red line) forms when two amino acids are covalently connected with water as a waste product. Colors are for illustration purposes; R1 and R2 represent additional atoms. B, In vitro translation with each column a different experiment with + indicating presence of an ingredient. Blank boxes show which ingredient was omitted. Below the table are protein gel electrophoresis results from the seven inputs above. Talking Point: In vitro experiment and the experimental setup. Fig. 2.20 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Proteins from Amino Acids
What method: gel electrophoresis (denaturing) stain all proteins dark Figure 2.20 Translation produces a polymer of amino acids to form a protein. A, A peptide bond (shown as a red line) forms when two amino acids are covalently connected with water as a waste product. Colors are for illustration purposes; R1 and R2 represent additional atoms. B, In vitro translation with each column a different experiment with + indicating presence of an ingredient. Blank boxes show which ingredient was omitted. Below the table are protein gel electrophoresis results from the seven inputs above. Talking Point: Investigators used normal protein gels and dyed all the proteins a dark color so they could be visualized. Fig. 2.20 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Proteins from Amino Acids
What What all ingredients…. Figure 2.20 Translation produces a polymer of amino acids to form a protein. A, A peptide bond (shown as a red line) forms when two amino acids are covalently connected with water as a waste product. Colors are for illustration purposes; R1 and R2 represent additional atoms. B, In vitro translation with each column a different experiment with + indicating presence of an ingredient. Blank boxes show which ingredient was omitted. Below the table are protein gel electrophoresis results from the seven inputs above. Talking Point: Always start with the controls. This positive control shows what happens when everything is working properly. …proteins produced Fig. 2.20 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Proteins from Amino Acids
What What omit DNA… Figure 2.20 Translation produces a polymer of amino acids to form a protein. A, A peptide bond (shown as a red line) forms when two amino acids are covalently connected with water as a waste product. Colors are for illustration purposes; R1 and R2 represent additional atoms. B, In vitro translation with each column a different experiment with + indicating presence of an ingredient. Blank boxes show which ingredient was omitted. Below the table are protein gel electrophoresis results from the seven inputs above. Talking Point: First experimental condition where DNA was left out of the reaction. Proteins produced so DNA is not required. …proteins produced Fig. 2.20 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Proteins from Amino Acids
What What omit energy source… What Figure 2.20 Translation produces a polymer of amino acids to form a protein. A, A peptide bond (shown as a red line) forms when two amino acids are covalently connected with water as a waste product. Colors are for illustration purposes; R1 and R2 represent additional atoms. B, In vitro translation with each column a different experiment with + indicating presence of an ingredient. Blank boxes show which ingredient was omitted. Below the table are protein gel electrophoresis results from the seven inputs above. Talking Point: Omitting ATP and GTP blocked protein synthesis. …no proteins produced Fig. 2.20 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Proteins from Amino Acids
What What omit tRNA… What Figure 2.20 Translation produces a polymer of amino acids to form a protein. A, A peptide bond (shown as a red line) forms when two amino acids are covalently connected with water as a waste product. Colors are for illustration purposes; R1 and R2 represent additional atoms. B, In vitro translation with each column a different experiment with + indicating presence of an ingredient. Blank boxes show which ingredient was omitted. Below the table are protein gel electrophoresis results from the seven inputs above. Talking Point: Omitting tRNA blocked protein synthesis. …no proteins produced Fig. 2.20 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Proteins from Amino Acids
What What omit ribosomes… What Figure 2.20 Translation produces a polymer of amino acids to form a protein. A, A peptide bond (shown as a red line) forms when two amino acids are covalently connected with water as a waste product. Colors are for illustration purposes; R1 and R2 represent additional atoms. B, In vitro translation with each column a different experiment with + indicating presence of an ingredient. Blank boxes show which ingredient was omitted. Below the table are protein gel electrophoresis results from the seven inputs above. Talking Point: Omitting ribosomes blocked protein synthesis. …no proteins produced Fig. 2.20 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Proteins from Amino Acids
What What omit mRNAs… What Figure 2.20 Translation produces a polymer of amino acids to form a protein. A, A peptide bond (shown as a red line) forms when two amino acids are covalently connected with water as a waste product. Colors are for illustration purposes; R1 and R2 represent additional atoms. B, In vitro translation with each column a different experiment with + indicating presence of an ingredient. Blank boxes show which ingredient was omitted. Below the table are protein gel electrophoresis results from the seven inputs above. Talking Point: Omitting mRNA blocked protein synthesis. …no proteins produced Fig. 2.20 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Proteins from Amino Acids
What omit amino acids… What Figure 2.20 Translation produces a polymer of amino acids to form a protein. A, A peptide bond (shown as a red line) forms when two amino acids are covalently connected with water as a waste product. Colors are for illustration purposes; R1 and R2 represent additional atoms. B, In vitro translation with each column a different experiment with + indicating presence of an ingredient. Blank boxes show which ingredient was omitted. Below the table are protein gel electrophoresis results from the seven inputs above. Talking Point: Omitting amino acids blocked protein synthesis. …no proteins produced Fig. 2.20 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Proteins from Amino Acids
What DNA is the only ingredient not used in translation. What Figure 2.20 Translation produces a polymer of amino acids to form a protein. A, A peptide bond (shown as a red line) forms when two amino acids are covalently connected with water as a waste product. Colors are for illustration purposes; R1 and R2 represent additional atoms. B, In vitro translation with each column a different experiment with + indicating presence of an ingredient. Blank boxes show which ingredient was omitted. Below the table are protein gel electrophoresis results from the seven inputs above. Talking Point: In addition to defining what was needed for translation, the investigators invented a good method that was used to deduce the genetic code. …no proteins produced Fig. 2.20 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Watch Translation Movie
OR sites.fas.harvard.edu/~biotext/animations/TRANSLATE20b.swf Figure 2.20 Translation produces a polymer of amino acids to form a protein. A, A peptide bond (shown as a red line) forms when two amino acids are covalently connected with water as a waste product. Colors are for illustration purposes; R1 and R2 represent additional atoms. B, In vitro translation with each column a different experiment with + indicating presence of an ingredient. Blank boxes show which ingredient was omitted. Below the table are protein gel electrophoresis results from the seven inputs above. Talking Point: The HHMI animation has good narration to help students notice key elements and synthesize what they have learned so far. The Harvard animation is more cartoon in nature. Fig link Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Decoding the First Codon
What What modern genetic code table with all possible codons no one knew about codons or which amino acids were coded by particular sequences Figure 2.21 Deciphering the first codon. A, Polymers of uracil (poly-U) mRNA were added to in vitro translation mixture conducted at three temperatures. Negative controls lacked the poly-U mRNA. B, The first codon decoded was for the amino acid phenylalanine (phe or F). Talking Point: Setting up the experimental question. Fig. 2.21 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Decoding the First Codon
What The very first experiment tested UUUUUUU to see which amino acid was encoded….. What Figure 2.21 Deciphering the first codon. A, Polymers of uracil (poly-U) mRNA were added to in vitro translation mixture conducted at three temperatures. Negative controls lacked the poly-U mRNA. B, The first codon decoded was for the amino acid phenylalanine (phe or F). Talking Point: First codon tested was UUU which ensured the code would not be read from DNA. Fig. 2.21 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Decoding the First Codon
measure polymerization over time What What Figure 2.21 Deciphering the first codon. A, Polymers of uracil (poly-U) mRNA were added to in vitro translation mixture conducted at three temperatures. Negative controls lacked the poly-U mRNA. B, The first codon decoded was for the amino acid phenylalanine (phe or F). Talking Point: Investigators measured polypeptide formation over time in different temperatures. Fig. 2.21 modified from Nirenberg and Leder. 1964
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Decoding the First Codon
measure polymerization over time What …UUUU... 0° C Figure 2.21 Deciphering the first codon. A, Polymers of uracil (poly-U) mRNA were added to in vitro translation mixture conducted at three temperatures. Negative controls lacked the poly-U mRNA. B, The first codon decoded was for the amino acid phenylalanine (phe or F). Talking Point: Polymerization of poly-phenylalanine at 0 C is steady. Fig. 2.21 modified from Nirenberg and Leder. 1964
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Decoding the First Codon
measure polymerization over time …UUUU... 24° C What Figure 2.21 Deciphering the first codon. A, Polymers of uracil (poly-U) mRNA were added to in vitro translation mixture conducted at three temperatures. Negative controls lacked the poly-U mRNA. B, The first codon decoded was for the amino acid phenylalanine (phe or F). Talking Point: The translation of poly-U mRNA is faster at 24 C. Fig. 2.21 modified from Nirenberg and Leder. 1964
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Decoding the First Codon
measure polymerization over time …UUUU... 37° C Figure 2.21 Deciphering the first codon. A, Polymers of uracil (poly-U) mRNA were added to in vitro translation mixture conducted at three temperatures. Negative controls lacked the poly-U mRNA. B, The first codon decoded was for the amino acid phenylalanine (phe or F). Talking Point: In vitro translation is very fast at 37 C (less than 5 minutes to completion). After the protein is produced, it begins to degrade at this warmer temperature. Fig. 2.21 modified from Nirenberg and Leder. 1964
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Decoding the First Codon
measure polymerization over time Figure 2.21 Deciphering the first codon. A, Polymers of uracil (poly-U) mRNA were added to in vitro translation mixture conducted at three temperatures. Negative controls lacked the poly-U mRNA. B, The first codon decoded was for the amino acid phenylalanine (phe or F). Talking Point: Negative controls show no polymerization regardless of the temperature. negative control reactions no polyU mRNA Fig. 2.21 modified from Nirenberg and Leder. 1964
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Decoding the First Codon
UUU encodes phenylalanine (phe = F) Figure 2.21 Deciphering the first codon. A, Polymers of uracil (poly-U) mRNA were added to in vitro translation mixture conducted at three temperatures. Negative controls lacked the poly-U mRNA. B, The first codon decoded was for the amino acid phenylalanine (phe or F). Talking Point: The first codon had been deciphered and the race was on to determine all 64. Fig. 2.21 modified from Nirenberg and Leder. 1964
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Decoding the Two More Codons
test …AAAA… Figure 2.22 Deciphering AAA and CCC codons. A, Poly-A and poly-C mRNAs were tested at two different temperatures. B, Genetic code determined for two additional codons at noted in table. Talking Point: Poly-A mRNA produced poly-lysine protein in vitro. lysine polymers (lys = K) Fig. 2.22 modified from Nirenberg and Leder. 1964
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Decoding the Two More Codons
test …CCCC… Figure 2.22 Deciphering AAA and CCC codons. A, Poly-A and poly-C mRNAs were tested at two different temperatures. B, Genetic code determined for two additional codons at noted in table. Talking Point: Poly-C mRNA produced polypeptide composed of all proline. lysine polymers (lys = K) Fig. 2.22 modified from Nirenberg and Leder. 1964
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The Genetic Code first 3 codons deciphered Fig. 2.23
Figure 2.23 Full genetic code used by plants, animals, bacteria and archaea. Detailed descriptions of each amino acid are available at this interactive web page ( Talking Point: The first three deduced codons. Fig. 2.23 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Stop and Start Codons 3 “stop codons” 1 “start codon” Fig. 2.23
Figure 2.23 Full genetic code used by plants, animals, bacteria and archaea. Detailed descriptions of each amino acid are available at this interactive web page ( Talking Point: 1 “start” codon and 3 stop codon (no amino acids). Start codon often is the first codon to be translated in a protein. 1 “start codon” Fig. 2.23 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Amino Acids with Six Codons
Figure 2.23 Full genetic code used by plants, animals, bacteria and archaea. Detailed descriptions of each amino acid are available at this interactive web page ( Talking Point: Several Integrating Questions ask you to explore this table more fully. Fig. 2.23 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Amino Acids with One Codon
Figure 2.23 Full genetic code used by plants, animals, bacteria and archaea. Detailed descriptions of each amino acid are available at this interactive web page ( Talking Point: Several Integrating Questions ask you to explore this table more fully. Fig. 2.23 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Integrating Concepts in Biology
PowerPoint Slides for Chapter 2: Central Dogma 2.4 Can cells pick and choose information? by A. Malcolm Campbell, Laurie J. Heyer, & Christopher Paradise Title Page Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Biology Learning Objectives
Apply the genetic code to deduce the protein encoded by a mRNA. Review different examples of non-linear information, and determine how they apply to the central dogma. ELSI Learning Objective Defend how biologists can be certain that they are learning new information if they cannot prove their conclusions. Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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NCBI Biological Information Database
Figure 2.24 NCBI website and databases. A, Screen shot of the NCBI home page with some links to other resources. Talking Point: NCBI is a portal to biological sequence data and bioinformatics tools. Fig. 2.24A Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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The Interface Changes Frequently
Figure 2.24 NCBI website and databases. A, Screen shot of the NCBI home page with some links to other resources. Talking Point: Students should not try to memorize how to perform these analyses since the interface changes often. Fig. 2.24A Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Is All Information Linear?
insulin mRNA Figure 2.24 NCBI website and databases. A, Screen shot of the NCBI home page with some links to other resources. B, Screen shot for Integrating Question 35 showing a dot plot of the human insulin mRNA compared to itself. Talking Point: This version was redrawn to show key elements. Key elements are the two axes labels and the purple diagonal line. Subsequent slides are real screen shots, but the NCBI version may change over time. insulin mRNA Fig. 2.24 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Is All Information Linear?
insulin mRNA Figure 2.24 NCBI website and databases. A, Screen shot of the NCBI home page with some links to other resources. B, Screen shot for Integrating Question 35 showing a dot plot of the human insulin mRNA compared to itself. Talking Point: Alignment of insulin mRNA with itself and displayed in a dotplot. insulin mRNA Fig. 2.24 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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NCBI Biological Information Database
What human insulin mRNA sequence aligned with itself same base #400 same base #300 first last bases same base #400 Figure 2.24 NCBI website and databases. A, Screen shot of the NCBI home page with some links to other resources. B, Screen shot for Integrating Question 35 showing a dot plot of the human insulin mRNA compared to itself. Talking Point: How to read a dot plot. Each “dot” represents an identical amino acid in the two comparison sequences. same base #300 first last bases Fig. 2.24 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Watch rER Animation Clip
start at 1:57 and stop at 2:27 igure 2.29 Electron micrograph of ribosomes. Ribosomes produce proteins either in the cytoplasm or into the rough endoplasmic reticulum. Ennist DL. Free and Bound Ribosomes. ASCB Image & Video Library. 2007; EDU-5. Talking Point: Reminder of how mRNA is translated by ribosomes and some translation takes place on the surface of the rER. Fig. 2.29b Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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BLAST Align Nucleotide Sequences
Integrating Question #34 Input to generate Figure 2.28. IQ #35 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Human Insulin mRNA vs Self
Integrating Question #34 Output for IQ 34. IQ #35 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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What did you get with mRNA vs gene?
1st 3 segments with nearly perfect sequence alignments 2nd Figure 2.24 NCBI website and databases. A, Screen shot of the NCBI home page with some links to other resources. B, Screen shot for Integrating Question 35 showing a dot plot of the human insulin mRNA compared to itself. Talking Point: If you put mRNA in top box, and gene in bottom box, you will get these results. Three segments correspond to the three exons with the biggest exon (#3) listed first (mRNA base #246). Note single SNP in first exon. 3rd IQ #35 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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What did you get with mRNA vs gene?
dotplot gene Figure 2.24 NCBI website and databases. A, Screen shot of the NCBI home page with some links to other resources. B, Screen shot for Integrating Question 35 showing a dot plot of the human insulin mRNA compared to itself. Talking Point: If you put mRNA in top box, and gene in bottom box, you will get these results. The three longest segments are the same three exons from the previous slide. The smaller segments show regions of repeating DNA sequences and can be ignored for now. mRNA IQ #35 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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What did you get with mRNA vs gene?
dotplot gene 3 exons Figure 2.24 NCBI website and databases. A, Screen shot of the NCBI home page with some links to other resources. B, Screen shot for Integrating Question 35 showing a dot plot of the human insulin mRNA compared to itself. Talking Point: If you put mRNA in top box, and gene in bottom box, you will get these results. The three longest segments are the same three from the previous slide. The smaller segments show regions of repeating DNA sequences and can be ignored for now. Note how the last bases on exon 1 are similar to the first bases of exon 2, so these two segments overlap in the dot plot. mRNA IQ #35 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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What did you get with mRNA vs gene?
dotplot 2 introns gene Figure 2.24 NCBI website and databases. A, Screen shot of the NCBI home page with some links to other resources. B, Screen shot for Integrating Question 35 showing a dot plot of the human insulin mRNA compared to itself. Talking Point: If you put mRNA in top box, and gene in bottom box, you will get these results. The DNA present in the gene (Y-axis) but not present in the mRNA are introns. Note there is DNA before exon 1 and after exon 3 that is in the insulin gene that does not code for the mRNA. mRNA IQ #35 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Insulin mRNA vs. Gene why overlap? why overlap? insulin gene
Integrating Question #35 Talking Point: Output when you align the insulin gene (Y-axis) with the insulin mRNA (X-axis). Existence of introns and exons shown. insulin mRNA IQ #35 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Base Matches for mRNA and Gene
Integrating Question #35 Talking Point: Nucleotide alignment for mRNA/cDNA (top rows) and gene (bottom rows). Note the three discontinuous regions and some overlapping mRNA bases used more than once (40-42 and 239 – 246). IQ #35 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Note Nucleotides Used Twice
Integrating Question #35 Talking Point: Nucleotide alignment for mRNA/cDNA (top rows) and gene (bottom rows). Note the three discontinuous regions and some overlapping mRNA bases used more than once (40-42 and 239 – 246). IQ #35 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Note Nucleotides Used Twice
Integrating Question #35 Talking Point: Nucleotide alignment for mRNA/cDNA (top rows) and gene (bottom rows). Note the three discontinuous regions and some overlapping mRNA bases used more than once (40-42 and 239 – 246). IQ #35 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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ORF Finder for NM_000207 IQ #37 Integrating Question #37
Talking Point: Screen shot of ORF finder using insulin mRNA. IQ #37 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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ORF Finder for NM_000207 IQ #37 Integrating Question #37
Talking Point: Result when you click on reading frame #3 ORF. The insulin protein (110 amino acids) is shown below, but before processing discussed later. IQ #37 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Human Insulin Translated
Integrating Question #37 Talking Point: Prior to posttranslational processing, the “preproinsulin” protein. IQ #37 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Insulin Translated vs Circulating
purified protein Integrating Question #38 Talking Point: Alignment and dotplot of translated protein (110 amino acids) and the 51 amino acids found in insulin (51 amino acids) purified from blood. The gap highlights the deleted amino acids from the middle. The signal sequence is not shown at all in the dotplot. translated ORF IQ #38 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Insulin Translated vs Circulating
purified protein removed amino acids posttranslationally Integrating Question #38 Talking Point: Alignment and dotplot of translated protein (110 amino acids) and the 51 amino acids found in insulin (51 amino acids) purified from blood. The gap highlights the deleted amino acids from the middle. The signal sequence is not shown at all in the dotplot. translated ORF IQ #38 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Insulin Translated vs Circulating
removed signal sequence purified protein Integrating Question #38 Talking Point: Alignment and dotplot of translated protein (110 amino acids) and the 51 amino acids found in insulin (51 amino acids) purified from blood. The gap highlights the deleted amino acids from the middle. The signal sequence is not shown at all in the dotplot. #1-24 translated ORF IQ #38 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Rough ER Figure 2.25 Electron micrograph of ribosomes. Ribosomes produce proteins either in the cytoplasm or into the rough endoplasmic reticulum (rER). Talking Point: Electron micrograph of rough ER with attached ribosomes as well as free-floating ribosomes in the cytoplasm. Fig. 2.25 micrograph by George Palade Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Rough ER lumen of ER sm lg Fig. 2.25
Figure 2.25 Electron micrograph of ribosomes. Ribosomes produce proteins either in the cytoplasm or into the rough endoplasmic reticulum (rER). Talking Point: Reminder of how mRNA is translated by ribosomes and some translation takes place on the surface of the rER. lumen of ER Fig. 2.25 micrograph by George Palade Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Insulin Translated vs Circulating
Integrating Question #38 Talking Point: Amino acid alignment after the signal sequence has been removed. Internal portion is removed AFTER insulin is folded and has disulfide bonds formed. See structure online. IQ #38 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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Insulin Translated vs Circulating
Integrating Question #38 Talking Point: Amino acid alignment after the signal sequence has been removed. Internal portion is removed AFTER insulin is folded and has disulfide bonds formed. See structure online. removed amino acids IQ #38 Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
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