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.
Q: What makes common bacterial infections hard to eradicate?
A: Increasing numbers of drug-resistant strains
Q: How is Zika virus primarily spread?
A: By the bite of an infected Aedes mosquito; also transmitted by sexual contact
Q: What was Robert Hooke’s contribution to microbiology using the microscope?
A: Robert Hooke was the first to describe microbes in his book Micrographia (1665), where he illustrated the fruiting structures of molds.
Q: What did John Tyndall discover about microbial structures?
A: spores have very high heat resistance and are difficult to destroy.
Q: What were some key developments and discoveries during the Golden Years of Microbiology (1854–1914)?
A: aseptic surgery, pure culture techniques, pasteurization, vaccines, and better microscopes.
Important discoveries were Bacillus anthracis, Mycobacterium tuberculosis, Vibrio cholerae, and Neisseria gonorrhoeae.
Q: Why are certain microorganisms essential for life?
A:
* Oxygen production, nitrogen fixation
* Decomposers
* Bioremediation
* Industry
Q: Who was Koch’s lab assistant that came up with a convenient culture dish?
A: Julius Richard Petri, who invented the Petri dish.
A. Light Source B. Obj lens C. Ocular Lens D. Stage E. Condenser F. Focusing knobs G. Diaphragm
- ___ Magnifies the image
2.___ Focuses the light
3.___ control amount of light that enter the Obj lens
4.___ Provide different magnifications - ___ Control amount of light
- ___ control intensity of light
- ___ holds specimen
- C
- E
- G
- B
- A
- F
- D
Q: What did Koch observe about the appearances of microbe colonies on solid media?
A: the colonies had different shapes, colors, sizes, and nutritional requirements.
Q: What tool uses visible light to study microorganisms and magnifies up to 1,000x?
A light microscope.
Q: Scanning probe microscope can view individual ______
Compound light microscope uses visible light to illuminate
______
A: Atoms
Cells
Q: What is the equation for total magnification?
A: total magnification = objective magnification X ocular
magnification (ALWAYS 10x)
Q: What microscope can magnify images over 100,000x?
A: The electron microscope.
Q: _____________ determines how much detail can be
seen
A: Resolving Power
Q: Which microscope can view individual atoms?
A: The scanning probe microscope.
Q: What magnification levels are typically used in light microscopes?
A: 4x, 10x, 40x, and 100x.
Q: What is the path of light in a light microscope?
A: specimen > objective lens > ocular lens > eye, where the magnified image is viewed.
Q: Resolution is enhanced with
lenses of higher magnification
(100x) by the use of ________________
A: Immersion Oil
Q: What improves contrast?
A: Staining
Q: How does immersion oil reduce light refraction in microscopy?
A: by minimizing the scattering of light rays, enabling more light to pass through the specimen
Q: What dyes are positively charged and bind strongly to
negatively-charged cell components?
A: Basic Dyes
Q: What dyes are negatively charged and bind strongly to
positively-charged cell components?
A: Acidic Dyes
Q: What is a drawback of staining cells?
(In what situation would you not want to stain cells?)
A: Staining can alter or damage cells, so it’s not ideal for studying living cells or dynamic processes in real time.
Q: What do electron microscopes use to image cells and how do they work?
A: use electrons instead of light and employ electromagnets as lenses.
They operate in a vacuum, and images taken are called electron micrographs.
Q: What are the two types of electron microscopes and their uses?
A: Transmission Electron Microscope (TEM): Used to view internal cell structures
Scanning Electron Microscope (SEM): Used to view surface details of specimens by
Name the disease:
-Caused by Mycobacterium tuberculosis
-transmitted by close contact and inhalation
– In the 1800’s killed ¼ of the population of
Europe
– Difficult to treat since the cell wall contains a wax-like substance that resists drying
Tuberculosis (TB) 1800s
Name the disease:
– Bacterium (Yersinia pestis) injected through rat flea bite enters lymph
– Transmission to humans can be through rat flea bites, handling infected rats (animals), or can be airborne
-Also termed the Black Death
Bubonic Plague (1346-1353)
Name the disease:
-Caused by Vibrio cholerae
-transmitted orally through contaminated food and water
– Causes severe diarrhea (you can lose up to 4 gallons of fluid per day!)
– If left untreated the extreme loss of fluid results
in collapse and death
– Treatment requires replacement of fluid and
electrolytes (Gatorade)
Cholera
-Causative agent: variola virus
-Symptoms start with a fever and leads to widespread rash that crust over and
scarring
-Now considered eradicated, in the early 1970s 10-15 million people contracted the disease and 2 million died each year
-physician
Small pox
__________ ________
developed the practice now known as vaccination: milkmaids who contracted cowpox were immune to
smallpox, he inoculated a boy with material from cowpox
lesions and it protected him from both diseases (1796
Edward Jenner
3 Factors contributing to emergence of diseases include
- Evolutionary changes
- Modern Transportation
- Increased exposure to infectious agents
When was covid-19 declared a pandemic?
March 2020
Monkeypox (Mpox)
Virus:
Transmission:
Symptoms:
Treatment:
Virus: Orthopoxvirus
Transmission: Found in rodents (direct human-human contact)
Symptoms: Flu-like symptoms, painful rash
Treatment: Vaccine and effective chemo
– Also known as swine flu
– First detected in the United States in 2009
▪ Declared a pandemic, or worldwide large-scale
outbreak, by WHO in 2009
H1N1 Influenza
– Also known as bird flu
– Primarily in waterfowl and poultry
– Sustained human-to-human transmission has not yet
occurred
Avian influenza A (H5N1)
Zika Virus
Transmission:
Symptoms:
Where was it discovered?
Transmission: bite of an infected Aedes mosquito; sexual contact
Symptoms: fever, rash, and joint
pain
Where was it discovered? Uganda
Name 3 antibiotic resistant infections
- Methicillin-resistant Staphylococcus aureus (MRSA)
- Clostridium difficile
- Mycobacterium tuberculosis
Name the disease:
-First identified in 1976 in Sudan and in the
Democratic Republic of the Congo
– Causes fever, hemorrhaging, and intravascular blood clotting
– Transmitted via contact with infected blood or body fluids
Ebolavirus disease
4 Common basic dyes include:
- Methylene blue
- Crystal violet
- Safranin
- Malachite green
what term describes cell shape and arrangement
Cell Morphology
Any cell that is not a perfect circle is considered what type of cell morphology
Coccobacillus
* Short round rod
