Microbiology Chapter 1 Vocabulary Practice

Vocabulary and key concepts from Microbiology Chapter 1, covering the history of microbiology, taxonomy, cell types, staining methods, and scientific discoveries of foundational scientists.

Microbiology

The study of microbes, which include bacteria, archaea, fungi, protists, helminths, and nonliving entities like viruses and prions.

Microbes

Small microscopic organisms that comprise at least half of the living biomass; less than $1\%$ of the total have been identified.

Bacteria

Living, prokaryotic, unicellular microorganisms that can be pathogenic or nonpathogenic; examples include those used in food production like pasteurization.

Archaea

Living, prokaryotic, unicellular, nonpathogenic organisms that often live in extreme or harsh environments.

Protists

Living, eukaryotic, nonspecific unicellular and multicellular organisms; unicellular examples include amoebae and multicellular examples include algae.

Fungi

Living, eukaryotic, unicellular and multicellular organisms; unicellular examples include yeast and multicellular examples include mushrooms.

Helminths

Living, eukaryotic, multicellular parasitic roundworms and flatworms.

Viruses

Non-living, non-cellular agents that infect animal, plant, or bacterial cells and can have a DNA or RNA genome; they require a host to survive.

Prions

Non-living infectious proteins discovered in the $1980s$ that are transmitted by transplant or ingestion; they are misshaped, affect host proteins, and must be incinerated to be killed.

Prokaryotic cells

The earliest lifeforms which are unicellular (bacteria and archaea), lack a nucleus, and are simpler than eukaryotic cells.

Eukaryotic cells

Cells that can be multicellular or unicellular (such as amoebae and yeast) and possess a nucleus.

Endosymbiotic theory

The theory stating that eukaryotic cells evolved from prokaryotic cells.

Pathogens

Microbes that cause disease; they account for less than $1\%$ of all microbes.

Opportunistic pathogens

Microbes that tend to cause disease only in a weakened or vulnerable immune system.

Aseptic Technique

Techniques used to prevent the spread of pathogens and the introduction of harmful microbes to a patient; used to safely study microbes in labs.

Golden Age of Microbiology ($1850$-$1920$)

A period characterized by a boom of discoveries, innovations in microscopes, and new techniques to isolate and grow microbes.

Robert Hooke

The first scientist to publish a description of cells; involved with the building blocks of the Golden Age and Cell Theory.

Antonie van Leeuwenhoek

The first scientist to see bacteria at $200x$ magnification, which he called "animalcules."

Spontaneous Generation

The theory that life comes from nonliving items.

Biogenesis

The theory that life comes from life; later proved by Louis Pasteur.

Louis Pasteur

Scientist who further proved biogenesis using S-necked flasks, developed pasteurization to slow spoilage, and created the first vaccines against anthrax and rabies.

Germ Theory of Disease

The theory stating that microbes cause infectious diseases, reinforced by Pasteur and Robert Koch.

Koch's Postulates of Disease

Four criteria used to determine the causative agent of a disease: ($1$) same organism present in every case, ($2$) organism isolated and grown in pure culture, ($3$) isolated organism causes disease in susceptible host, ($4$) organism re-isolated from the diseased animal.

HAI's (nosocomial infections)

Hospital-acquired infections.

Ignaz Semmelweis

The first professional to develop aseptic technique and recommend hand washing.

Joseph Lister

The scientist who discovered processes for aseptic surgery.

Florence Nightingale

The individual who established aseptic nursing practices.

Taxonomy

The study of how organisms can be grouped based on morphology (physical features) and physiological characteristics.

Binomial Nomenclature System

A two-name system established by Linnaeus where the first name is the genus (capitalized) and the second is the species; written fully first, then abbreviated.

Strains

Genetic variants of the same species.

Parasitism

A symbiotic relationship where one organism is hurt/harmed.

Mutualism

A symbiotic relationship where both organisms benefit.

Commensalism

A symbiotic relationship that is neutral for both organisms.

Normal Microbiota (flora)

The collection of bacteria, archaea, and eukaryotic microbes that reside in and on the human body, helping to train the immune system and digest food.

Transient Microbiota

Temporary passengers, including most acquired pathogens, that can be removed through hygiene.

Biofilms

Sticky communities of single or diverse microbial species that use fimbriae to attach to surfaces and secrete a protective matrix; an example is dental plaque.

Bioremediation

The industrial use of microbes to clean up waste.

Agar

A polysaccharide from seaweed used in growth media; first used by Koch and his team.

Pure Culture

A culture containing only a single species of microbe.

Streak Plate Technique

A method used to isolate a specific species of microbe by spreading them thinly enough to give rise to individual, identical colonies.

Basic Dyes

Alkaline, positively charged dyes attracted to negatively charged cell surfaces; includes methylene blue, crystal violet, safranin, and malachite green.

Acidic Dyes

Negatively charged dyes that do not easily enter cells and instead stain the background; used in negative staining (e.g., nigrosin).

Mordants

Chemicals such as iodine, alum, or tannic acid required in some staining procedures to fix or trap dye in a specimen.

Gram Staining

The most important differential stain that classifies bacteria as gram-positive (purple) or gram-negative (pink) based on cell wall structure.

Peptidoglycan

A protein-carbohydrate component found in cell walls; Gram-positive bacteria have a thick layer while Gram-negative have a thin layer.

Lipopolysaccharide (LPS)

A component of the outer membrane in Gram-negative bacteria that is dissolved by the alcohol-acetone solution during staining.

Acid-Fast Staining

A differential stain (detected via the Ziehl Neelsen Method) that distinguishes cells with waxy cell walls made of mycolic acid.

Immersion Oil

Oil used at $100x$ magnification in light microscopy to ensure light meets the lens and does not scatter.

Transmission Electron Microscopy (TEM)

A form of electron microscopy that shoots electrons through very thin specimens to visualize internal surfaces at up to $1$ million times magnification.

Scanning Electron Microscopy (SEM)

A form of electron microscopy used to visualize surface structures (like biofilms) in $3D$ by shooting electrons at the specimen.