Module 1 - History of Microbiology

Scientific Method

lengthy/continuing process of experimentation & analysis, idea testing, establishes “rules”

Explanation of natural phenomena before 1600

beliefs, superstition, argument, ideas not tested

Hypothetico-deductive method

the commonly used scientific method: observation, hypothesis, testable prediction, accept or reject hypothesis, evaluate or publish

Scientific method outcomes

accept hypothesis (not immediate, retested, published), reject hypothesis (new one created & process begins)

Hypothesis

educated guess based upon observation, rational explanation of an event, anyone can come up with one

Theory

explanation developed through extensive reproducible observations and tests, created by scientific community

Scientific law

statement of fact, accepted to be true & universal, can sometimes be expressed by mathematical equation

Science is a process

new things are discovered & old, long-held theories are modified or replaced with better ones as more data/knowledge is accumulated

Theory of evolution

accumulation of genetic changes; occur in organisms as they adapt to their environments (an observable phenomenon testable by science)

Evolution of life on earth

single-celled organism arose 3.5 billion years ago, then prokaryotes, then 2 billion years later eukaryotes

Microbiology

micron- small, biologia- study of living things, study of entities too small to be seen with unaided eye

Prokaryotes

small single cells and lack organelles (bacteria and archaea)

Eukaryotes

some single-celled, have nucleus, and organelles (protozoa, helminths, and fungi)

Viruses

not independently living cellular organism, particles, DNA or RNA wrapped in protein, depend on host cell’s machinery

Helminths

Worms, not microorganisms, but included due to similarity to bacterial disease (transmission, immune response)

Importance of microbes

perform essential environmental reactions, do work for us, sometimes cause infectious diseases

Earth & Microbes

microbes have shaped development of earth’s habitats and evolution of other life forms for billions of years, produces O2, essential for decomposition

Human use of microbes

baker’s & brewer’s yeast, cheeses & yogurt, antibiotics, drugs

Pathogen

any agent such as a virus, bacterium, fungus, protozoan, or helminth that cause disease