Microbiology Lecture - Historical Milestones and Bacterial Structure

Vocabulary practice flashcards covering historical pioneers in microbiology, early theories of disease, and bacterial structures and functions.

Robert Hooke

British scientist who was the first to describe cells in 1665 and published his visual observations in the book Micrographia.

Anton van Leeuwenhoek

Dutch merchant and politician inspired by Hooke who built simple microscopes and first described Animalcules, including bacteria, protozoa, sperm, blood cells, and capillaries.

Animalcules

The term used by Anton van Leeuwenhoek to describe microscopic living organisms he observed, which included protozoa and bacteria of all three basic shapes.

Redi's Covered Jar Experiment

A famous 1670s experiment using meat in covered and uncovered jars that refuted spontaneous generation for macroorganisms and developed the first controlled experiment.

Edward Jenner

British doctor who developed the first vaccination in 1796 by using pus from cowpox lesions to induce immunity against smallpox.

Semmelweiss

Hungarian doctor who introduced the use of lime water for hand and instrument disinfection (asepsis) in 1847 to prevent high mortality from childbirth fever.

Lister

Known as the Father of Aseptic Surgery, he expanded aseptic techniques into the operating theater in the 1850s using heat sterilization, wound and dressing disinfection, and air disinfection.

Pasteurization

A process developed by Louis Pasteur in 1857 using mild heat to remove most bacteria from liquids such as wine without destroying flavor.

Germ Theory of Disease

The theory written by Louis Pasteur stating that microorganisms are responsible for causing disease in humans, later proven experimentally by Robert Koch.

Pasteur's S-Flask Experiments

1865 experiments using open S-necked flasks that allowed oxygen in while preventing airborne microbes from entering, disproving spontaneous generation.

Attenuation

The process of weakening a pathogen to produce a vaccine, discovered accidentally by Louis Pasteur during chicken cholera experiments.

Koch's Postulates

A four-step experimental framework established by Robert Koch in 1875 to isolate and definitively prove the specific causative pathogen of a disease.

Bacillus anthracis

The bacterium identified by Robert Koch in 1875 as the causative agent of anthrax in cattle, proving the Germ Theory of Disease.

Alexander Fleming

Scientist who accidentally discovered the first antibiotic, penicillin, from Penicillium notatum mold in 1929.

Spontaneous Generation

The disproven belief that living organisms can arise spontaneously from non-living matter, such as maggots from rotting meat or eels from mud.

Miasma Theory

An obsolete theory proposing that diseases were transmitted through poisonous gases or toxic fumes rising from dead or diseased bodies.

The Golden Age of Microbiology

The era between 1850 and 1900 marked by rapid scientific discoveries and intense competition among researchers in identifying pathogens and aseptic methods.

Pasteur and Koch Accomplishments Summary

A timeline chart detailing major milestones of Louis Pasteur (such as Germ Theory, S-flask experiments, rabies vaccine) and Robert Koch (proving Germ Theory, pure culture methods, identifying causes of TB and cholera).

Prokaryotes

Organisms constructed of simple cells that lack membrane-bound organelles, such as bacteria.

Cocci

Bacterial cells that exhibit a round or spherical shape.

Bacilli

Bacterial cells that exhibit a rod-like shape.

Spirilli

Bacterial cells that exhibit a spiral or curved shape.

Strepto-

Bacterial arrangement prefix referring to cells arranged in chains.

Staphylo-

Bacterial arrangement prefix referring to cells grouped in grape-like clusters.

Diplo-

Bacterial arrangement prefix referring to cells occurring in pairs of two.

Palisade

Bacterial arrangement characterized by rod-shaped cells aligned side-to-side.

Bacterial Cell Membrane

A phospholipid bilayer lacking sterols that forms a required boundary controlling the entry and exit of molecules in bacterial cells.

Bacterial Genome

A single circular double-helical DNA chromosome located in the nucleoid region, managed by DNA gyrase and topoisomerase enzymes for coiling and uncoiling.

70S Ribosomes

Prokaryotic ribosomes composed of rRNA and polypeptides responsible for protein synthesis, distinct from 80S eukaryotic ribosomes.

Peptidoglycan

A macromolecule found in bacterial cell walls consisting of alternating NAG (N-acetyl glucosamine) and NAM (N-acetyl muramic acid) sugars cross-linked by tetrapeptide and peptide chains.

Gram-positive Cell Wall

A bacterial cell wall structure characterized by a thick peptidoglycan layer containing teichoic and lipoteichoic acids.

Gram-negative Cell Wall

A bacterial cell wall structure characterized by a thin peptidoglycan layer and an outer membrane containing lipopolysaccharide (LPS) layers and Lipid A endotoxins.

Teichoic Acid

Molecules embedded in Gram-positive bacterial cell walls that function in cellular anchoring, molecule transport, and identification.

Lipid A

An endotoxin component present in the lipopolysaccharide outer membrane layer of Gram-negative bacteria.

Folic Acid Synthesis

An essential pathway where bacteria act enzymatically on PABA molecules to synthesize precursors for purines and pyrimidines required for DNA and RNA construction.

Plasmids

Small, self-replicating, extra-chromosomal circular DNA segments in bacteria that confer specialized optional functions.

R Plasmids

Resistance plasmids that code for efflux pumps, drug-destroying enzymes, or drug-modifying enzymes to provide antibiotic resistance.

F Plasmids

Fertility plasmids containing genes that initiate bacterial conjugation and encode instructions for building sex pili.

Virulence Plasmids

Plasmids (also called T plasmids) that carry code for toxins or enzymes that cause host tissue damage during disease.

Bacteriocin Plasmids

Plasmids encoding proteins specifically designed to kill competing bacterial species.

Sex Pili

Temporary, tubular structures composed of pilin protein, coded by F plasmids, that connect partner bacteria to transfer DNA during conjugation.

Fimbriae

Short, numerous, hair-like projections made of pilin protein that function primarily in adhesion to environmental or host surfaces.

Flagella

Stiff, curved rotational structures made of flagellin protein that drive movement by rotating counterclockwise for runs and clockwise for tumbles.

Taxis

Bacterial movement in response to a stimulus, accomplished by increasing straight runs toward positive stimuli or increasing tumbles away from negative stimuli.

Lophotrichous

A flagellar arrangement featuring a cluster or tuft of flagella at one point on the bacterial cell.

Peritrichous

A flagellar arrangement where flagella cover the entire outer surface of the bacterial cell.

Amphitrichous

A flagellar arrangement where one or more flagella are located at both polar opposite ends of the cell.

Glycocalyx

A mucoid outer coating made of polysaccharides or glycoproteins that forms a loose slime layer, a dense capsule, or a shared biofilm.

Endospores

Dormant, non-reproductive bacterial structures containing dispicolinic acid and a peptidoglycan-protein spore coat that confer extreme resistance to heat and harsh conditions.

Sporulation

The process triggered by harsh environmental conditions where a bacterial cell removes water, adds dispicolinic acid, and coats its genome in peptidoglycan and protein layers to form a dormant spore.

Germination

The process triggered by favorable conditions where an endospore absorbs water, loosens its coat layers, and resumes metabolic activity as a vegetative cell.