Introduction to Prokaryotes: Bacteria and Archaea

These flashcards cover essential vocabulary and concepts related to prokaryotes, their characteristics, types, and ecological roles, as outlined in the lecture notes.

Prokaryotes

Single-celled organisms that lack a nucleus and membrane-bound organelles, including Bacteria and Archaea.

Endospore

A resistant, dormant structure formed by some bacteria to survive harsh conditions.

Peptidoglycan

A polymer consisting of sugars and amino acids that forms a mesh-like layer outside the plasma membrane, found in bacterial cell walls.

Gram-positive

Bacteria that have a thick peptidoglycan layer in their cell wall, which retains the purple dye used in Gram staining.

Gram-negative

Bacteria that have a thin peptidoglycan layer and an outer membrane, which does not retain the purple dye in Gram staining.

Fimbriae

Hairlike appendages on bacteria that allow them to attach to surfaces or other cells.

Chemotaxis

The movement of an organism in response to a chemical stimulus.

Nitrogen fixation

The process of converting atmospheric nitrogen (N2) into ammonia (NH3) by certain bacteria and archaea.

Bioremediation

The use of microorganisms to degrade or remove pollutants and toxins from the environment.

Mutualism

A symbiotic relationship where both organisms benefit from the interaction.

Pathogen

An organism that causes disease in another organism.

R Plasmids

Plasmids that carry genes providing resistance to antibiotics.

Transformation

The process by which prokaryotic cells take up foreign DNA from their environment.

Transduction

The transfer of genetic material from one bacterium to another via bacteriophages.

Conjugation

A form of genetic recombination in bacteria wherein DNA is transferred between two cells that are temporarily joined.

Cyanobacteria

Photosynthetic bacteria that obtain their energy through photosynthesis and are often called blue-green algae.

Bacterial reproduction

Primarily occurs through a process known as binary fission, where a single bacterial cell divides into two identical daughter cells.

Antibiotic resistance

The ability of bacteria to resist the effects of drugs that once killed them or inhibited their growth.

Biofilm

A structured community of bacterial cells enclosed in a self-produced polymeric matrix adhered to a surface.

Endotoxin

A toxin that is part of the outer membrane of certain bacteria and is released only upon cell lysis.

Exotoxin

A toxin released by bacteria into their environment; often highly toxic and can cause disease.

Virulence factors

Molecules produced by pathogens that contribute to the pathogenicity of the organism.

Archaea

Microorganisms similar to bacteria but genetically distinct, capable of surviving in extreme environments.

Plasmids

Small, circular pieces of DNA in bacteria that can replicate independently of chromosomal DNA, often carrying genes.

Transposons

Segments of DNA that can move within and between genomes, also known as 'jumping genes'

Bacteroides thetaiotaomicron

A species of bacteria that is part of the normal gut microbiota in humans and plays a role in the digestion of complex carbohydrates.