Microorganisms Definition and Characteristics

Definition and Characteristics

• Microorganisms are tiny living organisms that are too small to be seen with the naked eye
• They are typically measured in micrometers (μm) or nanometers (nm)
• Microorganisms can be found almost everywhere on Earth, including in soil, water, air, and the human body

Types of Microorganisms

• Bacteria: prokaryotic cells, no nucleus or membrane-bound organelles
  • Examples: E. coli, Staphylococcus aureus, Bacillus subtilis
• Viruses: not considered living cells, consist of genetic material surrounded by a protein coat
  • Examples: Influenza, HIV, Ebola
• Fungi: eukaryotic cells, have a nucleus and membrane-bound organelles
  • Examples: Yeast, Mold, Mushrooms
• Protists: eukaryotic cells, do not fit into any other category
  • Examples: Amoeba, Paramecium, Giardia

Microorganism Sizes

• Bacteria: 0.5-5.0 μm in diameter
• Viruses: 20-400 nm in diameter
• Fungi: 2-10 μm in diameter
• Protists: 1-100 μm in diameter

Microorganism Functions

• Decomposition: breaking down organic matter into simpler compounds
• Fixation: converting nitrogen gas into a usable form
• Fermentation: converting glucose into energy
• Pathogenesis: causing disease in humans, animals, and plants

Microorganism Interactions

• Symbiosis: living together in a close, often beneficial relationship
  • Examples: gut microbiome, coral-algae symbiosis
• Antagonism: competing with each other for resources
  • Examples: antibiotic production, competition for nutrients
• Mutualism: both organisms benefit from the interaction
  • Examples: mycorrhizal fungi, lichen formation

Microorganisms: Definition and Characteristics

• Microorganisms are tiny living organisms that are too small to be seen with the naked eye, typically measured in micrometers (μm) or nanometers (nm).
• They can be found almost everywhere on Earth, including in soil, water, air, and the human body.

Types of Microorganisms

• Bacteria: prokaryotic cells with no nucleus or membrane-bound organelles, examples include E. coli, Staphylococcus aureus, and Bacillus subtilis.
• Viruses: not considered living cells, consist of genetic material surrounded by a protein coat, examples include Influenza, HIV, and Ebola.
• Fungi: eukaryotic cells with a nucleus and membrane-bound organelles, examples include Yeast, Mold, and Mushrooms.
• Protists: eukaryotic cells that don't fit into any other category, examples include Amoeba, Paramecium, and Giardia.

Microorganism Sizes

• Bacteria: 0.5-5.0 μm in diameter.
• Viruses: 20-400 nm in diameter.
• Fungi: 2-10 μm in diameter.
• Protists: 1-100 μm in diameter.

Microorganism Functions

• Decomposition: breaking down organic matter into simpler compounds.
• Fixation: converting nitrogen gas into a usable form.
• Fermentation: converting glucose into energy.
• Pathogenesis: causing disease in humans, animals, and plants.

Microorganism Interactions

• Symbiosis: living together in a close, often beneficial relationship, examples include gut microbiome and coral-algae symbiosis.
• Antagonism: competing with each other for resources, examples include antibiotic production and competition for nutrients.
• Mutualism: both organisms benefit from the interaction, examples include mycorrhizal fungi and lichen formation.