Lab Make-Ups

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Lab Make-Ups

• If you missed the strawberry lab or the candy dye
  lab you need to Borden ASAP to sign-up.
• The Candy dye lab kit will be returning to Fred
  Hutch Thurs., March 1 and will not be available
  after that.

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Warm-up DNA Review 2/22/07

• Write the DNA strand and complimentary base pairs
  that match
• 1 AGC AGG CTT AGT ACT CGA
• 2 GCT AGT ACC CAT CTG GAT

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AGENDA

• Warm-up
• Stamp Obj. 12.3
• Go over dye lab results
• Notes Transcription/Translation
• In class activity transcription/translation
• Discuss lab on for Monday
• No homework

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Transcription and Translation Protein synthesis
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What we already know

• DNA encodes the information to make proteins
• DNA cannot leave the nucleus
• Protein synthesis occurs outside of the nucleus,
  on a ribosome

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How does it happen?
DNA encodes the information to make
RNA.........and RNA molecules function together
to make protein                                 
                                                  
                                                  
                 
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(No Transcript)
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Structure of RNA

• Single stranded
• Built of nucleotide
• 5-Carbon Sugar ribose sugar
• Phosphate Group
• Nitrogenous base
• Adenine, Uracil, Guanine, and Cytosine

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NO THYMINE IN RNA
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(No Transcript)
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3 Types of RNA

• Messenger RNA (mRNA)
• carries information to ribosomes for protein
  production
• Transfer RNA (tRNA)
• brings specified amino acids from the cytoplasm
  to the ribosomes where the protein chain is made
• Ribosomal RNA (rRNA)
• the ribosome and protein

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3 Types of RNA
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Transcription

• DNA ? mRNA

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Transcription

• molecule of DNA is copied into a complementary
  strand of mRNA
• Occurs in the nucleus

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How does it happen?

• DNA unzips and exposes one gene as a template
• A complementary strand of RNA is formed
• A U
• G C
• mRNA strand exits nucleus moves into cytoplasm
• The two strands of DNA re-attach and recoil

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(No Transcript)
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Try it yourself

• Transcribe Strand 1 of the DNA molecules below
• 1 - T T A G G A C T G C A A T T G
• 2 - A A T C C T G A C G T T A A
  C
• 1 - C A G T C C G A A C G T T T A
• 2 - G T C A G G C T T G C A A A
  T

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Answers

• A A U C C U G A C G U U A A C
• G U C A G G C U U G C A A A U

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Translation

• mRNA ? protein

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Translation

• mRNA is read a protein is created from amino
  acids
• Occurs at ribosome

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Steps of Translation

• 1. mRNA moves to ribosomes
• 2. rRNA on the ribosome binds to the mRNA and
  starts reading codons.
• Codons 3 letter code that specifies a
  particular amino acid.
• start codon AUG
• stop codon UAA, UAG, or UGA
• 3. AUG binds to the first anticodon of tRNA

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• 4. tRNA transfer amino acids until the rRNA
  reaches a stop codon on the mRNA
• 5. ribosome releases protein and mRNA
• protein to be used by the cell
• mRNA to synthesize more protein molecules

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mRNA-amino acid chart
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Try it yourself!

• DNA template strand
• DNA TACGATCGAACGTAT
• mRNA codon
• tRNA anticodon
• Amino Acids

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• Transcription/Translation video
• http//www.youtube.com/watch?v1GWI7qcQWbA
• Transcription/Translation Activity
• Tape your work into lab notebook, do not take
  home the main worksheet

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mRNA Activity

• Here is a strand of mRNA. Arrange your tRNA
  molecules to determine the sequence of Amino
  Acids that this mRNA codes for.
• AUG CUA UCA UCA UAU GGA GUA ACU ?
• AGU UUU CGC AUU CCG CAU ACA CGG GUU ?
• CUC CCU CAC AGG UGG GGG UGU CUA ACC ?
• UUA CCC GCA UCG UAA

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Mutations

• Mutations lead to mistakes in the proteins being
  made.
• Mutations can happen during DNA replication and
  change the blueprint of the cell
• Or
• During transcription or translation so a wrong
  protein or no protein is made

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Types of mutation

• Point mutation- one nucleotide changes
• Frameshift mutation- an insertion or deletion of
  a nucleotide that changes all codons after that
  point
• Chromosomal mutation- all of the genes on a
  certain chromosome can be affected. Or change
  the location of genes on the chromosome.

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Transcription

• The information in the DNA not only contains
  amino acid (aa) sequences, it also has junk
  DNA.
• Exon RNA that codes for a.a.
• Intron junk RNA/DNA
• Enzymes in the nucleus snip out the exon and the
  RNA molecule is protected and sent outside of the
  cell.

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mRNA splicing