DNA and RNA

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DNA and RNA

• Chapter 12

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12-1 DNA

• Griffith and transformation
• Griffith experiment
• Mice injected with pneumonia
• Transformation
• The process by which one strain of bacteria is
  changed by a gene or genes from another strain of
  bacteria

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12-1 DNA

• Avery and DNA
• DNA or nucleic acid inside is the material that
  is transferred during transformation

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12-1 DNA

• The Hershey-Chase experiment
• Bacteriophage
• Virus that infects bacteria
• Radioactive markers

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12-1 DNA

• The components and structure of DNA
• Chargaffs Rules
• Base pairing
• A pairs with T
• G pairs with C

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12-1 DNA

• X-Ray evidence
• The double helix
• Watson and Crick
• Two strands wrapped around each other

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12-1 DNA
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12-2 Replication

• DNA and Chromosomes
• Prokaryote
• One circular DNA molecule
• Eukaryote
• 1000 times the DNA

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12-2 Replication

• DNA length
• Roughly 1000 times the length of the cell it is
  in.

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12-2 Replication

• Chromosome structure
• DNA can be 1 meter in length
• Chromatin
• DNA and protein
• Histones
• Proteins that DNA wraps around
• Nucleosomes
• DNA and histones

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12-2 Replication

• DNA replication
• Copying genetic information
• Complimentary bases
• Replication fork
• Site where the chromosome seperates, and
  replication occurs

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12-2 Replication

• Duplicating DNA
• Copying DNA
• This is called replication
• Makes two new identical strands

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12-2 Replication

• How replication occurs
• Enzymes unzip the DNA strand
• DNA polymerase
• Proofreads the new strands

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12-3 RNA and Protein Synthesis

• Structure of RNA
• Long chain of nucleotides
• Differences from DNA
• Sugar is ribose
• RNA is single-stranded
• RNA contains uracil instead of thymine

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12-3 RNA and Protein Synthesis

• Types of RNA
• mRNA
• Messenger RNA
• Carry instructions for putting amino acids
  together to make proteins
• rRNA
• Ribosomal RNA
• Ribosomes put amino acids together
• Ribosomes are also made of RNA (60) and protein
  (40)
• tRNA
• Transfer RNA
• Transports amino acids to the ribosome

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12-3 RNA and Protein Synthesis

• Transcription
• RNA polymerase
• binds to DNA at a promoter site
• separates the two strands
• One of the DNA strands is used to make a copy or
  RNA strand

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12-3 RNA and Protein Synthesis

• RNA editing
• Introns
• Parts of the DNA that are not used to make
  proteins
• Exons
• Parts of the DNA that are used to make proteins
• Gene splicing
• Removing introns from the sequence

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12-3 RNA and Protein Synthesis

• The genetic code
• Polypeptide
• Chains of amino acids
• Codon
• Three nucleotide bases that represent an amino
  acid
• 64 possible codons from four letters
• Start codon
• Stop codon

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12-3 RNA and Protein Synthesis

• Translation
• Ribosome reads the instructions found on the mRNA
  for making polypeptide chains or proteins
• 4 step process
• Can you find them?

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12-3 RNA and Protein Synthesis

• Roles of DNA and RNA
• DNA is the master copy
• RNA is the blueprint or copy of the master plan
• Why do we need a blueprint?

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12-3 RNA and Protein Synthesis

• Genes and Proteins
• Genes contain instructions for making proteins
• Proteins can be enzymes which control chemical
  reactions
• Determine hair color, height, blood type, etc

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12-4 Mutations

• Kinds of mutations
• Mutations
• Changes in genetic material

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12-4 Mutations

• Gene mutations
• Point mutations
• Changes in one or some nucleotides
• Substitution not so serious
• Insertion or Deletion
• Frameshift mutations
• Insertions or deletions which can be very serious

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12-4 Mutations

• Chromosomal mutations
• Changes in the number or structure of chromosomes
• Deletions loss of all or part of a chromosome
• Duplications extra copies of parts of
  chromosomes
• Translocations part of a one chromosome breaks
  off and attaches to another
• Inversions reverse the direction of all or part
  of a chromosome

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12-4 Mutations

• Significance of mutations
• Most mutations are neutral
• Means they have little to no effect
• Mutations can cause disruptions
• Disorders
• Cancer
• Mutations can cause successful variations
• Polyploidy
• An organism has extra sets of chromosomes

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12-5 Gene Regulations

• Prokaryote gene regulation
• Operon
• A group of genes that operate together
• Two regulatory parts
• Promoter
• Binds RNA polymerase
• Operator
• Repressors attach to the operator and block
  transcription
• Presence of some substance causes the repressor
  to be to busy to lock the operator

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12-5 Gene Regulations
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12-5 Gene Regulations

• Eukaryotic Gene Regulation
• Genes are usually controlled individually
• Enhancers
• Draw many proteins that can bind to these
  enhancers
• TATA box
• TATATA
• TATAAA

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12-5 Gene Regulations

• Development and differentiation
• Differentiation
• Cells become specialized in structure and
  function
• Hox genes
• Control the differentiation of cells and tissues
  in the embryo