BACTERIOPHAGE MARTZ

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BACTERIOPHAGEMARTZ
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Today's experiment Exercise 7
Bacteriophage one-step growth

• Remember that..
• The Phage worksheet is due during the next lab
  period
• Continue working on your Environmental unknown
• Maintain your storage culture

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Bacteriophage (T4)

• Definition
• Obligate intracellular parasites that multiply
  inside of bacteria by using some or all of the
  host biosynthetic machinery
• T4 Phage
• One of the largest phage
• Specifically infect on Escherichia coli
  B strain

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Composition

• Bacteriophage contain Nucleic Acids and Proteins.
• Nucleic Acid can be DNA or RNA, depending upon
  the phage.
• Proteins function in infection and to protect the
  nucleic acid from nuclease in the environment.

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Structure (T4)

• Size
• Approximately 200 nm long and 80-100nm wide
• Head or Capsid
• Icosahedral (20 faced, triangular shape)
• Protective covering for the nucleic acid
• Tail
• A hollow tube through which the nucleic acid
  passes during infection.
• Surrounded by a contractile sheath.
• Base Plates
• Tail fibers

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The Parts

• A package of DNA/RNA
• A transport tube
• An attachment device

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Infection of Host Cells

• Adsorption
• The tail fiber attach to specific receptors on
  the bacterial cell.
• Irreversible attachment
• Sheath Contraction
• Nucleic Acid Injection

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Infection of Host Cells

• Adsorption

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Infection of Host Cells

• Replication
• Transcription of Phage DNA to Phage RNA
• Translation of Phage mRNA to Proteins
• Replicate more Phage DNA

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Infection of Host Cells

• Eclipse period
• During the eclipse phase, no infectious phage
  particles can be found either inside or outside
  the bacterial cell. The phage nucleic acid takes
  over the host biosynthetic machinery and phage
  specified m-RNA's and proteins are made.

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Infection of Host Cells

• Assembly
• Maturation stage
• Intracellular Accumulation Phase

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Infection of Host Cells

• Lysis
• After a while the bacteria begin to lyse due to
  the accumulation of the phage lysis protein and
  intracellular phage are released into the medium.
  The number of particles released per infected
  bacteria may be as high as 1000.

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Infection of Host CellsVIDEO
http//www.msnbc.msn.com/id/5870695/
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Infection of Host Cells
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The Experiment The Step by Step
0.1 ml
0.1 ml
1.0ml
0.1 ml
35
40
15
20
30
11,000,000
110,000,000
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Completing the Worksheet
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The Experiment Preparation
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The Experiment Execution
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The Experiment Execution
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The Experiment Execution
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The Experiment Execution
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The Experiment