Microbiologia

Cards · 40

Bacteria

Single-celled prokaryotic microorganisms that lack a membrane-bound nucleus.

Virus

A non-cellular infectious agent consisting of nucleic acid enclosed in a protein coat, requiring a host cell to replicate.

Fungi

Eukaryotic organisms, including yeasts and molds, that absorb nutrients from organic matter.

Archaea

A domain of single-celled prokaryotes distinct from bacteria, often living in extreme environments.

Protozoa

Single-celled eukaryotic microorganisms that are typically motile and heterotrophic.

Peptidoglycan

A polymer consisting of sugars and amino acids that forms a mesh-like layer outside the plasma membrane of most bacteria.

Gram-positive bacteria

Bacteria with a thick peptidoglycan cell wall that retains the crystal violet stain during Gram staining.

Gram-negative bacteria

Bacteria with a thin peptidoglycan layer and an outer membrane that do not retain crystal violet stain.

Endospore

A dormant, tough, and non-reproductive structure produced by certain bacteria to survive harsh conditions.

Plasmids

Small, circular, double-stranded DNA molecules distinct from a cell's chromosomal DNA.

Bacteriophage

A virus that specifically infects and replicates within bacteria.

Pathogen

A microorganism capable of causing disease in a host organism.

Commensalism

A symbiotic relationship where one organism benefits and the other is neither helped nor harmed.

Mutualism

A symbiotic relationship where both participating species benefit.

Parasitism

A relationship in which one organism benefits at the expense of another.

Biofilm

A complex community of microorganisms attached to a surface and embedded in a self-produced extracellular matrix.

Antigen

A molecule or structure that reacts specifically with antibodies and can trigger an immune response.

Antibody

A Y-shaped protein produced by plasma cells that neutralizes specific pathogens.

Antibiotic

A chemical substance produced by microorganisms or synthetically that inhibits or kills bacteria.

Sterilization

The complete elimination or destruction of all forms of microbial life, including spores.

Disinfection

The process of destroying or removing most pathogenic microorganisms on inanimate objects.

Pasteurization

A heat-treatment process that reduces the number of viable pathogens in liquids.

Fermentation

An anaerobic metabolic process in which microorganisms convert carbohydrates into alcohol or organic acids.

Aerobe

An organism that requires oxygen for growth and oxygen-based metabolism.

Anaerobe

An organism that does not require oxygen for growth and may be harmed by its presence.

Facultative anaerobe

An organism that can make ATP by aerobic respiration if oxygen is present, but can switch to fermentation if oxygen is absent.

Microaerophile

A microorganism that requires oxygen to survive, but at lower concentrations than in the atmosphere.

Prion

An infectious protein that causes neurodegenerative diseases by inducing misfolding of normal proteins.

Capsid

The protein shell that encloses the genetic material of a virus.

Binary fission

A method of asexual reproduction where a single cell divides into two identical daughter cells.

Conjugation

The direct transfer of genetic material between bacterial cells through cell-to-cell contact.

Transformation

The uptake and integration of naked extracellular DNA by a competent bacterial cell.

Transduction

The process by which foreign DNA is introduced into a cell by a virus or viral vector.

Lytic cycle

A viral reproductive cycle that results in the destruction of the infected cell and its membrane.

Lysogenic cycle

A viral reproductive cycle where the viral genome integrates into the host chromosome and replicates silently.

Normal flora

The population of microorganisms that live on and inside healthy human bodies without causing disease.

Microbiome

The collective genomes of all the microorganisms that reside in a environmental niche or host.

Endotoxin

A toxic component embedded in the outer membrane of Gram-negative bacteria released upon cell lysis.

Exotoxin

A toxic protein secreted by living bacteria into their environment.

Viroid

An infectious entity affecting plants, consisting solely of a short strand of circular RNA without a protein coat.