knowt logo

Microbiology is defined by techniques

  • Culture media for isolation and growth of organisms in pure culture

  • Biochemical to study cell components

  • Molecular and genetic techniques

  • Microbes are the oldest form of life

  • Largest mass of living material on Earth

  • Carry out major processes for biogeochemical cycles

  • Can live in places unsuitable for other organisms

  • Other life forms require microbes to survive.

All cells have the following in common:

  • Cytoplasmic membrane

    Barrier that separates the inside of the cell from the outside environment

  • Cytoplasm
    Aqueous mixture of macromolecules, ions, and proteins

  • Ribosomes
    Site of protein synthesis

Genetic material
• AllcellsstoretheirgeneticinformationasDNA
• The information is divided into functional units called genes

• Genome
• Acell'sfullcomplementofgenes

• Chromosome
• A genetic element carrying genes essential to cellular function

• Plasmid

• A piece of DNA that carries non-essential genes

Eukaryotes

  • Membrane bound nucleus

  • Membrane bound organelles

  • Complex internal organization

  • Division by mitosis and meiosis.

Protists – unicellular or multi-cellular

without differentiation into tissues

Protozoa – animal-like microorganisms

Algae – photosynthetic plant-like microorganisms

Slime molds and water molds – filamentous

Fungi – Unicellular (yeasts), filamentous (molds), or multi-cellular (mushrooms).

Prokaryotes

No membrane bound nucleus or organelles

Simple internal structure
Divide by binary fission

Most are unicellular

Bacteria

• Genetically diverse

• Extremely diverse metabolic styles
• Includes both pathogens and non-pathogens

Archaea
• Genetically and biochemically distinct from bacteria

• Also have diverse metabolism
• Never pathogenic
• Most famous for living in extreme environments.

Viruses

Acellular infectious particles
Obligate intracellular parasites

Lack independent metabolism

  • No ribosomes

  • No ribosomal RNA

Cannot be classified with other microbes.

Microbiology is defined by techniques

  • Culture media for isolation and growth of organisms in pure culture

  • Biochemical to study cell components

  • Molecular and genetic techniques

  • Microbes are the oldest form of life

  • Largest mass of living material on Earth

  • Carry out major processes for biogeochemical cycles

  • Can live in places unsuitable for other organisms

  • Other life forms require microbes to survive.

All cells have the following in common:

  • Cytoplasmic membrane

    Barrier that separates the inside of the cell from the outside environment

  • Cytoplasm
    Aqueous mixture of macromolecules, ions, and proteins

  • Ribosomes
    Site of protein synthesis

Genetic material
• AllcellsstoretheirgeneticinformationasDNA
• The information is divided into functional units called genes

• Genome
• Acell'sfullcomplementofgenes

• Chromosome
• A genetic element carrying genes essential to cellular function

• Plasmid

• A piece of DNA that carries non-essential genes

Eukaryotes

  • Membrane bound nucleus

  • Membrane bound organelles

  • Complex internal organization

  • Division by mitosis and meiosis.

Protists – unicellular or multi-cellular

without differentiation into tissues

Protozoa – animal-like microorganisms

Algae – photosynthetic plant-like microorganisms

Slime molds and water molds – filamentous

Fungi – Unicellular (yeasts), filamentous (molds), or multi-cellular (mushrooms).

Prokaryotes

No membrane bound nucleus or organelles

Simple internal structure
Divide by binary fission

Most are unicellular

Bacteria

• Genetically diverse

• Extremely diverse metabolic styles
• Includes both pathogens and non-pathogens

Archaea
• Genetically and biochemically distinct from bacteria

• Also have diverse metabolism
• Never pathogenic
• Most famous for living in extreme environments.

Viruses

Acellular infectious particles
Obligate intracellular parasites

Lack independent metabolism

  • No ribosomes

  • No ribosomal RNA

Cannot be classified with other microbes.