Microbiology Flashcards

Flashcards generated from microbiology lecture notes.

How did Louis Pasteur help disprove spontaneous generation?

He showed that life arises only from pre-existing life, using swan-necked flasks with sterile broth which remained sterile unless exposed to outside air. This proved microorganisms come from the environment, not spontaneous generation.

Describe the scientific method?

A systematic approach to understanding the natural world through observation, hypothesis, experimentation, data analysis, conclusion, and communication.

Explain why life could not exist without the activities of microorganisms

Microorganisms drive energy capture, perform nutrient cycling, decompose organic matter, enable nitrogen fixation, break down pollutants, and support ecosystem stability.

How is the normal microbiota important to human health?

Prevents infections, aids digestion, enhances immune system development, competes with harmful microbes, consumes nutrients, produces protective compounds, may reduce allergies and asthma, and influences brain chemistry and weight management.

List four commercially important benefits of microorganisms

Aid in food production, are crucial in biotechnology for producing antibiotics and insulin, help in waste management through bioremediation, and play a role in agriculture by enhancing soil fertility through nitrogen fixation.

What characteristics of microorganisms make them important research tools?

Their rapid growth rates, ability to adapt to diverse environments, and genetic simplicity enable scientists to conduct experiments and manipulate genetic material effectively.

List three factors that contribute to the emergence of infectious diseases.

Microbial evolution, widespread use of antimicrobial medications, and changes in human society.

In the designation Escherichia coli B, which part of the name indicates the genus? Which part indicates the species? Which part indicates the strain?

Escherichia indicates the genus, coli indicates the species, and B indicates the strain.

Why are viruses not microorganisms?

Viruses are acellular, cannot reproduce on their own, and do not carry out metabolic processes independently. They are not alive.

What are the basic components of a virus?

• Nucleic acid: DNA or RNA (never both); can be ss or ds; carries genetic info

• Capsid: Protein coat made of capsomeres; protects genome; can be helical, icosahedral, or complex

• Envelope (optional): Lipid layer from host + viral proteins; helps with entry into host cells

• Spikes: Glycoproteins on envelope/capsid; help attach to host cell receptors

• Enzymes (some viruses): e.g. reverse transcriptase in retroviruses; aid replication/integration

The property of endospores that led to confusion in the experiments on spontaneous generation is their…

Heat resistance

The Golden Age of Microbiology was a time when…

Most pathogenic bacteria were identified

If all prokaryotes were eliminated from the planet…

All animals would die

All of the following are emerging infectious diseases except…

Smallpox

All of the following are biological domains except…

Prokaryota

Which name is written correctly?

Staphylococcus epidermidis

Members of which pairing are most similar in appearance to each other?

Archaea and bacteria

If you wanted to increase your chances of obtaining a member of the Archaea (rather than a member of another domain), which would be the best site to obtain a sample?

A 95 degree celsius hot spring in Yellowstone National Park

Viruses contain what…

Both protein and nucleic acid

Antonie van Leeuwenhoek could not have observed

Viruses. His microscopes weren’t powerful enough (only up to ~300x magnification) and they are too small to be seen by the naked eye. Viruses require electron microscopes, which weren't a thing until the 1930s.

What foods could not be on the menu at a “Microbe-Free” banquet?

Foods like yogurt and cheese could not be on the menu, as they rely on microbial activity for production.

Who would you nominate for the Nobel Prize and why?

Louis Pasteur due to his groundbreaking work in germ theory and the development of pasteurization, which significantly advanced food safety and public health.

How to differentiate a virus from a viroid?

Viruses have a protein coat (capsid), while viroids do not, being composed only of RNA.

Why are extremophile archaea more intensively studied than those that do not?

Due to their unique adaptations, biotechnological potential, insights into the origins of life, and novel metabolic pathways.