MKBN Definitions SU 1

A set of 25 vocabulary flashcards covering essential microbiology terms drawn from the lecture notes.

Pathogenic

Describes organisms that have the ability to cause disease.

Non-pathogenic

Describes organisms that do not cause disease.

Opportunistic pathogen

An organism that can cause disease only when the host’s resistance is lowered; normally commensal.

Infectious disease

A disease caused by pathogenic microorganisms that can spread directly or indirectly from one person to another.

Saprophyte

An organism that lives on and feeds from dead animal or plant tissue; acts as a decomposer.

Parasite

A living organism that lives in or on another living organism (the host), using the host’s resources and potentially causing harm or death.

Infectious agent

Any material capable of causing infection; the five major types are bacteria, viruses, fungi, protozoa, and helminths.

Bacteria

Single-celled prokaryotic microorganisms with a simple structure and no nucleus.

Algae

Eukaryotic, chlorophyll-containing organisms without true roots, stems, or leaves; perform photosynthesis and often live in water.

Fungi

Multicellular, eukaryotic, non-photosynthetic microorganisms that may be parasitic or saprophytic and play key roles in nutrient cycling.

Protozoa

Usually unicellular eukaryotic microorganisms commonly found in water and soil; some are pathogenic.

Viruses

Submicroscopic infectious agents that replicate only inside living cells and infect all forms of life.

Prions

Infectious protein molecules capable of causing certain diseases in humans and animals.

Viroids

Smallest known infectious agents; single-stranded RNA molecules that cause disease in certain plants and lack a protein coat.

Mycology

The study of fungi; scientists in this field are called mycologists.

Zoonoses

Infectious diseases that are transmissible from animals to humans (zoonotic diseases).

Communicable

Able to be transmitted from one person to another; contagious or infectious.

Simple microscope

A microscope containing a single magnifying lens that produces a magnified, erect, virtual image of an object placed within its focus.

Biogenesis

The theory that life originates only from pre-existing life, never from non-living matter.

Abiogenesis

The theory (spontaneous generation) that life can arise from non-living matter; earliest life forms originated from inorganic substances.

Pasteurization

A heating process that kills pathogenic microorganisms in products such as milk or wine, making them safe for consumption.

Postulates

Fundamental criteria used to establish a causal relationship between a microbe and a specific disease.

Opportunistic infection

An infection caused by an opportunistic pathogen when the host’s resistance is lowered.

Saprophytic

Describes the lifestyle of organisms that obtain nutrients from dead organic matter.

Capsid

The protein coat that surrounds and protects the genetic material of a virus.