Protein Synthesis and Regulation

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Chapter 10

• Protein Synthesis and Regulation

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III. Protein Synthesis

• A. DNA is code nucleus
• 1. exists in the nucleus
• 2. transcription makes an RNA strand
• 3. RNA strand moves to cytoplasm
• 4. RNA used to synthesize proteins

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III. Protein Synthesis

• B. Transcription
• 1. Definition - make RNA
• 2. Procedure
• a. RNA polymerase reads the DNA and matches the
  bases
• b. RNA polymerase attaches incoming bases to the
  new strand but not permanently to the DNA

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III. Protein Synthesis

• B. Transcription
• 1. Definition - make RNA
• 2. Procedure
• a. RNA polymerase reads the DNA and matches the
  bases
• b. RNA polymerase attaches incoming bases to the
  new strand but NOT to the DNA
• c. creates a strand of RNA
• d. RNA moves to cytoplasm

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III. Protein Synthesis

• B. Transcription
• 3. three types of RNA used for translation

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III. Protein Synthesis

• B. Transcription
• 3. three types of RNA used for translation
• a. m-RNA
• 1) is the code
• 2) read 3 nucleotides at a time codon
• 3) each codon codes for one amino acid

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Fig. 10.1
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Table 10.1
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III. Protein Synthesis

• B. Transcription
• 3. three types of RNA used for translation
• a. m-RNA
• b. r-RNA
• 1) assembles the protein chain
• 2) p-site holds amino acid chain
• 3) a-site is for incoming amino acid
• 4) reaction site for condensation (dehydration
  synthesis)
• 5) e-site for ejection of empty t-RNA

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Fig. 10.4

A
P
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Fig. CO 9
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III. Protein Synthesis

• B. Transcription
• 3. three types of RNA used for translation
• a. m-RNA
• b. r-RNA
• c. t-RNA
• 1) brings an amino acid to the ribosome
• 2) has anticodon to match codon of m-RNA
• 3) each amino acid anticodon has specific amino
  acid

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Fig. 9.14
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III. Protein Synthesis

• C. Translation
• 1. Definition - make a protein
• 2. Process

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Fig. 9.16
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III. Protein Synthesis

• C. Translation
• 1. Definition - make a protein
• 2. Procedure
• a. initiation
• b. elongation
• c. termination

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Fig. 9.15
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III. Protein Synthesis

• D. How mRNA works

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Fig. 9.17
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III. Protein Synthesis

• Recap
• SKIP
• gene families, transposons

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Fig. 9.18
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III. Protein Synthesis

• D. Regulation in Prokaryotes
• 1. regulatory sites
• a. promoters beginning of a gene indicates
  start of code
• b. operator after promoter - controls access
  to rest of gene
• c. repressor binds to operator - turns off gene
• d. activator binds before gene and allows RNA
  polymerase to bind to promoter
• e. inducer binds to repressor so gene is turned
  on

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III. Protein Synthesis

• D. Regulation in Prokaryotes
• 2. example - operon theory
• a. lac operon
• b. bacteria

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Fig. 9.19
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III. Protein Synthesis

• E. Regulation in Eukaryotes
• 1. chromosome level - DNA packing
• 2. transcription level - regulators on DNA
• 3. transcript level - introns and exons
• 4. exit nucleus - improper sequences held back
• 5. degrade RNA in cytoplasm
• 6. translation - regulators on message
• 7. protein level - modification of inactive
  protein, degrade active protein

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IV. Mutations

• A. Mechanisms
• 1. Damage to DNA
• a. x-rays - break DNA strands
• b. UV - changes bonds in bases
• c. chemicals - change bases themselves
• 2. Errors in replication

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Table 9.1
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IV. Mutations

• B. Types of Mutations
• 1. point mutations
• a. substitution - changes one amino acid in
  protein

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Fig. 9.23
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IV. Mutations

• B. Types of Mutations
• 1. point mutations
• a. substitution - changes one amino acid in
  protein
• b. insertion or deletion - changes order of the
  bases and so changes all of the amino acids

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Fig. 9.23
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IV. Mutations

• B. Types of Mutations
• 2. whole chromosome mutations
• a. inversion
• b. translocation
• c. deletion/insertion
• d. duplication