Characteristics of Microorganisms

Study Notes

Bacteria: prokaryotic, cell wall composed of peptidoglycan
- Examples: E. coli, Staphylococcus aureus
Archaea: prokaryotic, cell wall composed of pseudopeptidoglycan
- Examples: methanogens, thermophiles
Viruses: not considered living cells, require host cells to replicate
- Examples: influenza, HIV
Fungi: eukaryotic, cell wall composed of chitin
- Examples: yeast, mold
Protists: eukaryotic, diverse group of microorganisms
- Examples: protozoa, algae

Decomposition: break down organic matter into simpler compounds
Nutrient Cycling: convert elements into forms usable by other organisms
Symbiosis: form relationships with other organisms, such as mutualism or commensalism
Pathogenesis: cause disease in other organisms
Food Production: used in fermentation, such as bread, beer, and yogurt

Competition: compete with other microorganisms for resources
Cooperation: work together with other microorganisms to achieve a common goal
Communication: use signaling molecules to communicate with other microorganisms
Antagonism: inhibit the growth or activity of other microorganisms

Sterilization: complete elimination of microorganisms
Disinfection: reduction of microorganisms to a safe level
Antimicrobial Agents: chemicals or drugs that inhibit or kill microorganisms
Personal Protective Equipment (PPE): used to prevent exposure to microorganisms

Microorganisms are typically measured in micrometers (μm) and can be single-celled or multicellular.
They can be prokaryotic (lacking a true nucleus) or eukaryotic (having a true nucleus).
Microorganisms can be found in almost every environment, including extreme environments.

Bacteria are prokaryotic and have a cell wall composed of peptidoglycan, with examples including E. coli and Staphylococcus aureus.
Archaea are also prokaryotic, but have a cell wall composed of pseudopeptidoglycan, with examples including methanogens and thermophiles.
Viruses are not considered living cells and require host cells to replicate, with examples including influenza and HIV.
Fungi are eukaryotic and have a cell wall composed of chitin, with examples including yeast and mold.
Protists are a diverse group of eukaryotic microorganisms, with examples including protozoa and algae.

Decomposition is the process of breaking down organic matter into simpler compounds.
Nutrient cycling involves converting elements into forms usable by other organisms.
Symbiosis involves forming relationships with other organisms, such as mutualism or commensalism.
Pathogenesis is the ability of microorganisms to cause disease in other organisms.
Microorganisms are used in food production, such as in fermentation, to produce items like bread, beer, and yogurt.

Competition occurs when microorganisms compete with each other for resources.
Cooperation involves working together with other microorganisms to achieve a common goal.
Microorganisms use signaling molecules to communicate with each other.
Antagonism involves inhibiting the growth or activity of other microorganisms.

Sterilization is the complete elimination of microorganisms.
Disinfection reduces the number of microorganisms to a safe level.
Antimicrobial agents are chemicals or drugs that inhibit or kill microorganisms.
Personal Protective Equipment (PPE) is used to prevent exposure to microorganisms.