Microbiology and Microorganisms Overview

Microbiology and Microorganisms

• Microbiology is the study of microorganisms, which are microscopic entities including bacteria, archaea, viruses, fungi, algae, and protozoa.
• Microorganisms are categorized into three main groups: bacteria, archaea, and eukarya, based on cellular structures and genetic characteristics.

Groups of Microorganisms

• Bacteria: Unicellular prokaryotes that lack membrane-bound organelles; reproduce asexually through binary fission; have diverse metabolic capabilities.
• Archaea: Similar to bacteria in structure but genetically distinct; often found in extreme environments; possess unique lipid membranes and cell walls.
• Eukarya: Organisms characterized by eukaryotic cells that contain a nucleus; includes fungi, plants, animals, and protists; more complex than prokaryotes.

Prokaryotes vs. Eukaryotes

• Prokaryotes: Generally smaller and simpler; lack a nucleus and membrane-bound organelles; genetic material is a single circular chromosome; examples include bacteria and archaea.
• Eukaryotes: Larger and more complex; possess a nucleus and various membrane-bound organelles; genetic material is organized into multiple linear chromosomes; examples include fungi, plants, and animals.

Pathogens vs. Non-Pathogenic Microorganisms

• Pathogenic microorganisms: Cause disease in hosts; examples include pathogenic bacteria, viruses, and some fungi.
• Non-pathogenic microorganisms: Typically beneficial or neutral; play essential roles in processes like fermentation, nutrient cycling, and digestion.

Structures for Locomotion and Attachment

• Bacteria: Utilize structures like flagella for movement and pili (or fimbriae) for attachment to surfaces or host cells.
• Eukaryotic Cells: Use cilia and flagella for movement; have various adhesive proteins on surfaces to facilitate attachment.

Helminths

• Helminths are large, multicellular parasitic worms; classified into several groups, including flatworms (platyhelminths) and roundworms (nematodes).
• General life cycle often includes multiple stages such as eggs, larvae, and adult worms; may require intermediate hosts for development.
• Transmission methods include ingestion of eggs, direct contact with contaminated soil, or via vectors such as insects, depending on the type of helminth.