Microbiology Lecture Flashcards

A set of question-and-answer flashcards covering key concepts from the microbiology lecture notes.

What is microbiology?

The study of small microorganisms not visible to the naked eye, including bacteria, fungi, yeasts, molds, viruses, and parasites, covering all aspects of microbes.

Where are microbes found?

They are everywhere—almost every environment on Earth—and there are more microbes in the human gut than people on the planet.

What is the difference between pathogens and non-pathogenic microbes?

Pathogens cause disease; non-pathogenic microbes do not harm humans and can be harmless or beneficial.

Name three important roles of microbes in the environment.

Base of the aquatic food chain; soil microbes decompose waste and provide nitrogen; some are photosynthetic and some intestinal microbes manufacture vitamins.

What are industrial microbes commonly used for?

Producing acids, alcohols, vitamins, and drugs; involved in food production (cheese, yogurt); helping control pathogenic microbes in foods.

What are the two names every microbe has, and how are they formatted?

Genus and species; genus capitalized, species lowercase, both italicized when typed.

How should genus names be abbreviated in scientific text?

Abbreviate after first use by taking the first letter of the genus plus the full species name (e.g., E. coli).

Which group of organisms does not follow the same naming rules as others?

Viruses; they do not follow the same genus–species naming conventions.

What does the name Staphylococcus aureus illustrate about scientific names?

Staphylococcus aureus references shape and environment: 'staphylo' = clustered cells, 'coccus' = spherical, 'aureus' = golden color.

List the major types of microbes covered in microbiology.

Bacteria, Archaea, Fungi, Protozoa, Algae, Multicellular Animal Parasites, and Viruses.

What are the main features of Bacteria?

Prokaryotic, unicellular organisms; lack membrane-bound nucleus; shapes include bacillus (rod), coccus (round), and spirillum (spiral).

What is the bacterial cell wall composed of and how is it used for classification?

Peptidoglycan; the amount of peptidoglycan determines Gram+ versus Gram- classification.

How do bacteria reproduce and move?

Reproduce by binary fission (asexual); some are motile with flagella; others use pili or fimbriae.

What characterizes Archaea?

Prokaryotes with cell walls lacking peptidoglycan; include methanogens, halophiles, thermophiles; not known human pathogens.

What are fungi and how do they obtain nourishment?

Eukaryotic, can be unicellular or multicellular; absorb nutrients; not photosynthetic; form spores.

What are fungal spores and why are they important?

Fungal spores enable dispersion to new places and are a major means of fungal movement.

What are protozoa and how do they move?

Eukaryotic, unicellular, motile organisms using pseudopods, cilia, or flagella; some are disease-causing; replication can be sexual or asexual.

What is algae and what is their role?

Photosynthetic eukaryotes, unicellular or multicellular; produce oxygen and essential carbohydrates; usually do not require organic nutrients from the environment.

What are multicellular animal parasites and why are they included in microbiology?

Helminths (roundworms and tapeworms); not microbes themselves but studied for medical importance using similar identification techniques.

What are viruses and how do they reproduce?

Acellular particles with a capsid and sometimes an envelope; not living; require a host cell's machinery to replicate.

What are the three domains of life according to Woese and Fox?

Bacteria, Archaea, and Eukarya (which includes Protists, Fungi, Plants, and Animals).

What are the two opposing ideas about the origin of life prior to Pasteur?

Biogenesis: life comes from life; Spontaneous generation: life arises spontaneously from nonliving matter.

What did Francesco Redi demonstrate about spontaneous generation?

Maggots do not appear on meat when flies are prevented from landing, supporting biogenesis.

What were Needham and Spallanzani's differing conclusions about spontaneous generation?

Needham claimed boiled broths became microbe-rich (supporting spontaneous generation); Spallanzani argued sealed boiled broths remained sterile (against spontaneous generation).

What did Louis Pasteur prove about microbes and air?

Microbes are present in the air and on materials; but sterilized broth in a closed environment can remain sterile if microbes are kept out.

What is Pasteur's Swan-neck flask experiment demonstrating?

Dust and microorganisms cannot reach the broth; air can enter without introducing life; supports biogenesis and disproves spontaneous generation.

Name some practical outcomes of Pasteur's work.

Aseptic technique; heat can kill microbes (pasteurization); blocking microbial access to nutrients prevents growth.

What were Jenner's, Snow's, and Pasteur's contributions to blocking disease?

Jenner: smallpox vaccine using cowpox; Snow: mapped cholera outbreaks to a contaminated water source; Pasteur: pasteurization and understanding spoilage by microbes.

What did Koch's postulates establish?

A framework proving a specific microbe causes a disease: same microbe in every case, isolate in pure culture, infect a healthy host to reproduce disease, re-isolate the microbe.

Who discovered penicillin and why is it significant?

Alexander Fleming discovered penicillin; Florey and Chain mass-produced it; it revolutionized treatment of bacterial infections.

What are some disciplines included in Modern Microbiology?

Bacteriology, Mycology, Parasitology, Immunology, Virology, Recombinant DNA Technology, and Epidemiology.

What is the difference between normal microbiota and pathogens?

Normal microbiota (flora) are harmless or beneficial; pathogens are microbes that cause disease.

What are some major global challenges facing microbiologists today?

High mobility and rapid spread of diseases, emerging and re-emerging infections, antimicrobial resistance, climate change effects on habitats, and potential biological threats.

What is bacteriology?

The study of bacteria, including their physiology, ecology, genetics, and pathogenicity.

What is mycology?

The study of fungi, including their taxonomy, ecology, and uses.

What is parasitology?

The study of parasites, their biology, life cycles, interactions with hosts, and the diseases they cause.

What is immunology?

The study of the immune system, including its structure, function, and the body's response to pathogens.

What is virology?

The study of viruses, including their structure, classification, and effects on living organisms.

What is recombinant DNA technology?

A molecular biology technique that involves combining DNA from different sources to create genetically modified organisms or to produce specific proteins.

What is epidemiology?

The study of the distribution, patterns, and determinants of health and disease conditions in defined populations.