Bacteria and Archaea

Binomial System

A naming convention for microorganisms using the format Genus species.

Genus

The first part of the binomial name, always capitalized.

Species

The second part of the binomial name, always lowercased.

Italicization

Both genus and species names should be italicized in print or underlined when written.

Bacteria

Microorganisms that are alive and capable of carrying out all necessary life activities.

Biofilms

Groups of bacteria that enhance each other's survival through cooperation.

Pleomorphism

Variation in size and shape among cells of a single bacterial species.

Coccus

A round or circular bacterial shape.

Bacillus

A rod-shaped bacterium.

Spirillum

A spiral-shaped bacterium.

Peptidoglycan

A structural component of bacterial cell walls providing support and protection.

Lipopolysaccharide

A component of Gram-negative bacteria's outer membrane, highly immunogenic.

Gram Stain

A technique used to differentiate bacteria based on cell wall composition.

Mycoplasmas

Bacteria that naturally lack a cell wall and are resistant to lysis.

Mycolic Acid

A long-chain fatty acid found in the cell walls of Mycobacterium, contributing to pathogenicity.

Acid-fast Stain

A staining technique used for bacteria with mycolic acids that do not retain crystal violet.

Selective Permeability

The ability of the cell membrane to allow certain substances to pass while blocking others.

Porin Proteins

Proteins that span the outer membrane, allowing small molecules to penetrate.

Capsule Stain

A staining method that differentiates the capsule from the bacterial cell.

Exotoxins

Toxins secreted by bacteria that target specific structures in host cells.

Endotoxins

Components of Gram-negative bacteria that do not target host cells but are recognized by the immune system.

Flagella

Appendages that provide movement to bacteria.

Chemotaxis

Movement of bacteria in response to chemical signals.

Fimbriae

Small, bristle-like fibers that provide adhesion to surfaces.

Pili

Long, rigid structures used for attachment and DNA transfer in Gram-negative bacteria.

Plasmids

Non-essential, circular pieces of DNA that can confer protective traits.

Central Dogma

The process of DNA being transcribed to RNA and then translated to protein.

Ribosomes

Cellular structures made of RNA and protein, essential for protein synthesis.

Endospores

Dormant structures formed by some bacteria to withstand harsh conditions.

Archaea

A distinct group of prokaryotic microorganisms with unique genetic and structural characteristics.