Chapter 01 – The Main Themes of Microbiology

Vocabulary flashcards covering major terms, concepts, scientists, and techniques introduced in Chapter 01.

Microbiology

The branch of biology that studies organisms too small to be seen with the naked eye.

Microorganism (Microbe)

Any microscopic organism, including bacteria, archaea, fungi, protozoa, helminths, viruses, and prions.

Bacteria

Single-celled prokaryotes lacking a nucleus; one of the major cellular groups of microbes.

Archaea

Prokaryotic microbes genetically and structurally distinct from bacteria; many inhabit extreme environments.

Fungi

Eukaryotic organisms such as molds and yeasts that obtain nutrients by decomposing organic matter.

Protozoa

Single-celled eukaryotes that are usually motile and lack a cell wall.

Helminths

Multicellular parasitic worms studied in microbiology because they cause human disease.

Viruses

Acellular infectious agents composed of nucleic acid (DNA or RNA) enclosed in a protein coat, sometimes with a lipid envelope.

Prions

Infectious, misfolded proteins that can transmit disease without nucleic acids.

Microbiologist

A scientist who studies the structure, function, genetics, ecology, and evolution of microbes.

Medical Microbiology

The branch that investigates microbes capable of causing diseases in humans and animals.

Public Health Microbiology

Field that monitors and controls disease spread in communities; includes epidemiology.

Epidemiology

The study of the distribution and determinants of disease in populations.

Immunology

Study of the body’s defenses, including cells and molecules that respond to infection, vaccination, allergy, etc.

Industrial Microbiology

Use of microbes to manufacture products such as amino acids, enzymes, beer, and vitamins; safeguards food and water.

Biotechnology

Any industrial or commercial use of living organisms or their products to create useful goods.

Agricultural Microbiology

Explores interactions between microbes, crops, and livestock to improve agriculture.

Environmental Microbiology

Examines the roles of microbes in natural habitats such as soil, water, and the earth’s crust.

Evolution

The cumulative genetic changes in populations of organisms over time as they adapt to environments.

Theory of Evolution

A well-supported, testable explanation for how evolution occurs; considered a fundamental natural law.

Eukaryote

Cell or organism with a membrane-bound nucleus and organelles; includes animals, plants, fungi, and protists.

Akaryote (Prokaryote)

Cell lacking a true nucleus; encompasses bacteria and archaea.

Ubiquitous

Present everywhere; used to describe the nearly universal distribution of bacteria.

Photosynthesis

Conversion of light energy into chemical energy; first performed by bacteria (anoxygenic) and later produced oxygen (oxygenic).

Photosynthetic Microorganisms

Bacteria and algae that generate more than 70 % of atmospheric oxygen.

Decomposition

Microbial breakdown of dead matter and wastes, recycling nutrients in ecosystems.

Recombinant DNA Technology

Genetic manipulation of organisms to produce new products or GMOs.

Genetically Modified Organism (GMO)

Plant, animal, or microbe whose genes have been altered through recombinant DNA techniques.

Bioremediation

Use of microorganisms to detoxify or restore polluted environments.

Pathogen

Any virus, bacterium, fungus, protozoan, or helminth capable of causing disease.

Communicable Disease

Illness that can be transmitted from one host to another.

Noncommunicable Disease

Illness not caused by infectious microbes and not spread between hosts.

Emerging Disease

Newly identified infection appearing in a population for the first time.

Reemerging Disease

Older infection once under control but increasing again, often due to resistance or lapses in public health.

Malaria

Mosquito-borne protozoan disease killing ~450,000 people yearly; preventable with bed nets.

Helicobacter pylori

Bacterium now known to cause most gastric ulcers.

Eukaryotic Cell

Larger cell type containing nucleus and organelles such as mitochondria and chloroplasts.

Prokaryotic Cell

Smaller cell lacking organelles; characteristic of bacteria and archaea.

Organelle

Membrane-bound intracellular structure performing a specific function (e.g., nucleus, mitochondrion).

Acellular Microorganism

Infectious agent lacking cellular structure, e.g., viruses and prions.

Spontaneous Generation

Disproved idea that life arises from nonliving matter; refuted by Pasteur’s swan-neck flask experiment.

Scientific Method

Systematic process of observation, hypothesis formation, experimentation, and conclusion.

Hypothesis

Tentative, testable explanation for an observation or question.

Deductive Reasoning

Applying general principles to make specific predictions.

Inductive Reasoning

Developing general principles by observing specific cases.

Theory (Scientific)

Comprehensive explanation supported by a vast body of evidence and not yet disproven.

Sterile

Completely free of all living forms, including spores and viruses.

Endospore

Heat-resistant, dormant structure formed by certain bacteria; discovered by Tyndall and colleagues.

Aseptic Techniques

Procedures that prevent microbial contamination, pioneered by Joseph Lister.

Germ Theory of Disease

Concept that specific diseases are caused by specific microorganisms (Koch, Pasteur).

Pasteurization

Mild heating process invented by Louis Pasteur to kill pathogens in liquids.

Polymerase Chain Reaction (PCR)

1980s technique that amplifies specific DNA sequences exponentially.

CRISPR Technology

2013 genome-editing method using bacterial immune mechanisms for precise DNA modification.

Robert Hooke

First to record observations of microbes (1600s) using an early microscope.

Antonie van Leeuwenhoek

Fabric merchant who built simple microscopes and described “animalcules.”

John Tyndall

Scientist who demonstrated the heat resistance of airborne microbes.

Oliver Wendell Holmes

Physician who noted lower infection rates in home births than hospital births.

Ignaz Semmelweis

Introduced hand-washing to reduce puerperal fever in maternity wards.

Joseph Lister

Surgeon who applied antiseptics to surgical practice, founding modern asepsis.

Louis Pasteur

Disproved spontaneous generation, developed pasteurization, and linked microbes to disease.

Robert Koch

Established postulates tying specific microbes to specific diseases.

Nomenclature

System of assigning scientific names to organisms.

Classification

Ordering organisms into hierarchical taxa based on relationships.

Identification

Determining an organism’s traits to assign it a correct taxonomic position.

Binomial System

Two-part scientific naming format: Genus (capitalized) + species (lowercase), both italicized.

Taxonomic Categories

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species—ranging from broadest to most specific.

Phylogeny

Evolutionary history and relatedness among groups of organisms.

Three Domains

Highest taxonomic rank: Bacteria, Archaea, and Eukarya.

Small-Subunit rRNA (ssuRNA)

Highly conserved ribosomal RNA used as a molecular chronometer in taxonomy.