Chapter 1 Flashcards
Q: What is microbiology?
A: The study of microorganisms, which are organisms too small to be seen with the naked eye.
Q: What are the major groups of microorganisms?
A: Bacteria, Archaea, Fungi, Protozoa, Algae, Viruses, and Multicellular Animal Parasites.
Q: What is the germ theory of disease?
A: Microorganisms are the causes of many diseases
Q: What was Louis Pasteur’s conclusion disproving spontaneous generation?
microorganisms are present in the air and can contaminate sterile solutions but do not arise spontaneously from non-living matter (Swan-Necked experiment)
Q: What is spontaneous generation?
A: The discredited theory that life arises spontaneously from non-living matter.
Q: What is pasteurization?
A: The process of heating liquids to a temperature that kills most bacteria and reduces the risk of spoilage and disease.
Q: What is aseptic technique?
A: Procedures that prevent contamination by unwanted microorganisms using carbolic acid to sterilize surgical instruments and clean wounds.
Q: What is a vaccine, and who is credited with its discovery?
A: a preparation of weakened or killed pathogens used to induce immunity.
Edward Jenner is credited with developing the first vaccine using cowpox to protect against smallpox.
Q: What did Robert Koch contribute to microbiology?
A: Koch’s postulates which experimentally verified the germ theory of disease
Q: What is the significance of Alexander Fleming’s discovery? 1928
A: He discovered penicillin, the first antibiotic, which revolutionized the treatment of bacterial infections.
Q: What are 4 types of microscopes used in microbiology?
A: Light microscope, Electron microscope, Confocal microscope, and Scanning probe microscope.
Q: What is the purpose of staining in microscopy?
A: increases contrast and allows for the visualization of specific structures within microorganisms.
Q: What are the steps in the Gram staining procedure?
A: Crystal violet stain, iodine treatment, alcohol decolorization, and safranin counterstain.
Q: What is the difference between Gram-positive and Gram-negative bacteria?
A: Gram-positive: thick peptidoglycan layer and no outer membrane, staining purple
Gram-negative: thin peptidoglycan layer and an outer membrane, staining pink.
Q: What is Monkeypox and where is it found?
caused by orthopoxvirus; found in rodents and endemic in West and Central Africa.
Q: What is the function of the bacterial cell wall?
A: provide structure and shape to the cell and protect against osmotic pressure.
Q: What are the symptoms and transmission of Monkeypox?
A: Flu-like symptoms and rash, transmitted human-to-human by direct contact
Q: What is the role of the cytoplasmic membrane in bacteria?
A: selective barrier, regulating the movement of substances in and out of the cell.
Q: What are emerging infectious diseases (EIDs)?
A: Diseases that are new and increasing in incidence.
Q: What is the role of ribosomes in bacteria?
A: Ribosomes are the site of protein synthesis in bacterial cells.
Q: What is an endospore?
A: A highly resistant, dormant structure formed by some bacteria to survive extreme conditions.
Q: What is the resolution in microscopy?
A: The ability of a microscope to distinguish two points as separate.
Q: What is the difference between simple and differential staining?
A: Simple staining uses a single dye to color microorganisms
Differential staining uses multiple dyes to differentiate one bacterial group from another
Q: Two most common differential stains
- Gram stain
- Acid-fast stain
Q: What are obligate anaerobes?
A: Bacteria that cannot survive in the presence of oxygen.
Q: What is the role of oxygen in bacterial growth?
A: Oxygen is required by aerobic bacteria for energy production, while anaerobic bacteria may be harmed or killed by oxygen.
Q: What are the 2 most common bacterial morphologies and 4 others?
A:
(Most Common)
- Coccus (spherical)
- Bacillus (rod-shaped)
(Others)
- Coccobacillus (Short round rod)
- Vibrio (curved rod)
- Spirillum (spiral)
- Spirochete (rigid spiral)
Q: What is peptidoglycan?
A: forms the cell wall in most bacteria, consisting of sugars and amino acids.
Q: What are the three special stains?
- Capsule stain
- Endospore stain
- Flagella stain
Q: What are acid-fast bacteria, and why are they important?
A: have waxy cell walls that resist decolorization by acids during staining.
This group includes important pathogens like Mycobacterium tuberculosis.
Q: What is the importance of studying antibiotic resistance in bacteria
A: crucial for understanding how bacteria evade antimicrobial agents, which is key to developing new treatments and managing resistant infections.
Q: What is the function of bacterial capsules?
A: protect the cell and can contribute to virulence.
Q: What is pure culture?
A: Cells from only a single type
of microorganism
Q: What is the purpose of enrichment culture techniques?
To isolate microbes with specific metabolic characteristics from nature.
Q: What is the significance of the 16S rRNA gene in bacterial identification?
A: highly conserved among bacteria, making it useful for identifying and classifying bacteria based on genetic sequences.
What are the domains described below?
single-celled organisms, have no membrane bound nucleus, do not contain any other organelles, and cytoplasm surround by cell wall
Domain Bacteria and Archaea
Q: What is transient microbiota?
A: colonizes the superficial layers of the skin and is easier to remove by routine hand hygiene.
Q: Who established the system of scientific nomenclature?
A: Carolus Linnaeus (1735).
What are the domains described below?
Organisms contain membrane bound nucleus, Contains internal organelle, May be single and/or
multicellular
Domain Eukarya
Q: What is a superbug?
A: A bacterium that has developed resistance to multiple antibiotics.
Q: The two-word naming system where the first word is the Genus name and the second word is the Species name.
A: the binomial naming system
Q: What are prions and how do they cause disease?
A: misfolded proteins that can induce other proteins to misfold
Q: What are the differences between prokaryotic and eukaryotic cells?
A: Prokaryotic cells lack a nucleus and membrane-bound organelles (single celled) , while eukaryotic cells have both (multicellular)
Q: What are 3 roles of normal microbiota in human health?
A: 1. prevent the growth of harmful microbes
2. assist in digestion
3. contribute to the immune system.
Q: What is the significance of Joseph Lister in microbiology?
A: introduced aseptic surgical techniques
Q: What is an antibiotic?
A: A substance that inhibits the growth of or kills bacteria.
Q: Define Microbiome
A: a group of
microbes that live stably on/in the human body
Q: What is the origin of the term “vaccination,” and what is the protection called?
A: The term is derived from “vacca,” the Latin word for cow, and the protection is called immunity.
Q: How many body cells, bacterial cells, and microbial cells is an adult human composed of?
30 trillion body
40 trillion bacterial
1-10 microbial
T or F: Scientific names in organism nomenclature can be descriptive or honor a scientist
T
Q: What 5 factors related to the host can affect pathogen impact?
- Age/life history
- injury
- immunity
- nutrition
- social interactions
Q: What 5 environmental factors can influence pathogen behavior?
Oxygen
temperature
pollution stress
health care access
socioeconomic status
Q: Who proposed the Three Domain Classification system?
A: Carl Woese (1977).
Q: What characteristics of the pathogen itself can influence its effect?
A: Virulence, number, size, location, growth rate
Q: For what 3 reasons is ribosomal RNA (rRNA) used in studying evolutionary relationships?
- present in all living organisms
- highly conserved sequences
- sequences differ b/w species
Q: What was Carl Woese’s discovery about rRNA from methanogens?
rRNA from methanogens is distinct from Bacteria and Eukarya. (Classified as archaea)
Q: What is the significance of organisms being in the same domain?
A: share properties that distinguish them from organisms in other domains.
Q: What is the purpose of sequencing rRNA genes in organisms?
A: To figure out how different organisms are related through evolution.
Q: What new group did Carl Woese name based on his rRNA findings?
A: Archaea
Q: What is biogenesis
A: Living organisms arise
from preexisting life
Q: John NeedHam’s Experiment:
Needham boiled broth to kill existing microbes, then sealed it in flasks. After some time, the broth became cloudy with microbial growth
Is this Spontaneous generation or Biogenesis?
A: Spontaneous generation
Q: What does LUCA stand for, and why is it important?
A: LUCA stands for Last Universal Common Ancestor, and it’s the common ancestor of all living things.
Q: Who is the Father of Epidemiology?
A: John Snow
Q: Which types of cells are found in the domains Bacteria and Archaea?
A: Prokaryotes (unicellular).
Q: Name the four types of eukaryotic organisms.
A: Algae, Protozoa, Fungi, and Helminths.
Q: Which eukaryotic organisms can be unicellular or multicellular?
A: Algae, Fungi, and Helminths
Q: What are the three types of infectious agents (non-living)?
A: Viruses, Viroids, and Prions.
T or F: Only Single-celled Eukarya are
microbes
T:
– Algae
– Fungi
– Protozoa
Q: What did John Snow discover about the cholera outbreak in London in 1853?
A: Cholera cases were linked to a single water source, a pump.
Q: What is the causative agent of smallpox?
A: Variola virus
Q: Who conducted the experiment in 1668 involving maggots?
A: Francesco Redi.
Q: How many different microbes can cause disease?
A: Almost 2,000
Q: Symptoms of Smallpox
A: fever that leads to a rash
Q: What idea was Francesco Redi testing, and what did he conclude?
A: He tested spontaneous generation and concluded that maggots only came from flies laying eggs, not from the meat itself (biogenesis).
Q: What was Francesco Redi trying to find out with his experiment using sealed jars?
A: He wanted to see if maggots could develop on meat without flies laying eggs on it.
Q: What did Lazzaro Spallanzani do in his experiment (1765), and what were the results when the flask was open versus sealed?
A: He boiled nutrient solutions in flasks. When the flask was open, the gravy became filled with microorganisms. When the flask was sealed, the gravy remained free of microorganisms.
Q: What scientific idea was Spallanzani testing, and what conclusion did he reach?
A: He was testing spontaneous generation versus biogenesis. His experiment showed that microorganisms did not spontaneously generate; they only appeared when the flask was open, supporting biogenesis.
