Ch. 1 - The Microbial World Flashcards
What is a microbe (microorganism)?
What is required to see a microbe?
organism too small to be seen with the unaided eye
req. high magnification using microscope
What are the four major groups of microbes?
BVFP
- bacteria
- viruses
- fungi
- parasites
What is the study of bacteria called?
Give an example of a bacteria
bacteriology
E. coli
What is the study of viruses called?
Give an example of viruses
virology
HIV
Herpes virus
What is the study of fungi called?
Give an example of fungi
mycology
mold = cold = multicellular
yeast = warm = unicellular
What is the study of parasites called?
Give an example of parasites
parasitology
protozoan parasite
worms
Are microbes always harmful? Why or why not?
No, less than 1% of the time microbes can be harmful. 99% of the time microbes are beneficial to humans
What are the four important roles that microbes play that are beneficial to humans?
- ecological roles
- bioremediation
- commercial uses
- applications in medicine
Ecological roles of microbes refers to the __________ _________ of microbes in the _________
natural role
environment
List and describe the three ecological roles of microbes.
What microbes facilitate the different types of ecological roles?
How are these roles beneficial to humans?
Decomposers of organic waste (ex: dead tree) - bacteria and fungi - breakdown waste and recycle elements back into nature
Photosynthesis - bacteria (cyanobacteria) and protozoa (algae) - produce oxygen
Nitrogen Fixation - bacteria in environment (roots in soil) capture free N2 and convert it into nitrates used in plant development -> humans eat plants
Bioremediation refers to the __________ _________ of microbes in the _________
non-natural (artificial) role
environment
Explain what we mean when we say that bioremediation refers to a non-natural role of microbes
it’s an artificial process developed by human needs where microbes are introduced into an area that they are not originally found in
Generally describe how bioremediation can be beneficial to humans
certain bacteria can use pollutants as an energy source or can produce enzymes that breakdown toxic waste
Provide examples of how bioremediation is used today
oil spills - bacteria are artificially introduced into oceans to breakdown/remove oil (toxic substance) from the ocean
fixes drained clogs - bacterial enzymes are found in drain cleaners that help to remove clogs without adding harmful chemicals to the environment
Commercial uses of microbes refers to the role of microbes…
in the food and beverage industry
Which microbial groups are commercially used?
Name specific examples
bacteria
- dairy products (cheese,yogurt)
- cosmetic procedures (Botox)
fungi (yeast)
- alcoholic beverages (wine,beer)
- breads
How are microbes applied in medicine?
What are some examples of antibiotics that kill bacteria?
some microbes produce substances used as antibiotics that can kill harmful bacteria
Penicillin, Neomycin
Penicillin comes from…
Who discovered it?
fungal mold (gills of mushroom)
Fleming
How do scientist use penicillium mold to produce the antibiotic penicillin?
penicillium mold (fungal mold) is found on gills of mushroom
scientist collect mold and grow it by adding sugar
scientist separates the penicillin from the mold
collected penicillin is purified and can be used as antibiotic medicine
Microbes can be characterized as either
_________ (____%). ________
or
________ (____%). ________
harmless (99%). nonpathogenic
harmful (<1%). pathogenic
Harmful microbes are known as _____________.
pathogens (pathogenic microbes)
Define the term pathogen
live agents capable of causing disease (harm) in a host
Provide examples of diseases caused by pathogens.
Know which is the pathogen (P) and which is the disease (DZ)
Include what microbial group they are derived from.
TNS
fungus (yeast) - Tinea Pedis (P) - athletes foot (DZ)
bacterium - Neisseria gonorrhoeae (P) - gonorrhea (DZ)
virus - SARS-CoV-2 (P) - COVID-19 (DZ)
TRUE or FALSE: Normal microbiota are pathogens that play an important role in human health and disease prevention
False, normal microbiota are non-pathogenic because they do not cause harm to the human host
Normal microbiota is AKA…
It plays an important role in…
normal flora (“good bacteria”)
human health and disease prevention
Define normal microbiota (hint: what is it?)
resident microbes that are normally found in INSIDE and OUTSIDE the human body and cause NO harm to the human host
TRUE or FALSE: normal microbiota ALWAYS benefits the human host
False, normal microbiota SOMETIMES benefit the human host
(but it will NOT cause harm, hence nonpathogenic)
In what ways does normal microbiota play an important role in human health and disease prevention?
- produces useful substances that humans cannot make (like vitamin K)
ex: bacteria, like e. coli (colon), produce vitamin K in colon to help clot blood - normal microbiota will begin to overgrow to prevent overgrowth of harmful microbes = no room for invaders = prevents overgrowth of microbes
Provide examples of where in/on the human body normal microbiota can be found.
Be sure to include the name of the specific normal microbiota.
streptococci - mouth
staphylococci - skin
e. coli - colon
NOTE: are all bacteria
Describe the major contribution of van Leeuwenhoek.
If applicable, who is he known as?
- father of microbiology
- first scientist to observe live microorganisms through magnifying lens and made detailed drawings of them
Describe the major contribution of Jenner.
If applicable, who is he known as?
- father of vaccines
- created first vaccine (vaccine against smallpox) and eliminated smallpox (from smallpox virus)
- How?: observed milkmaids with Cowpox virus (cowpox) were protected from Smallpox. took material from cowpox pustule and injected it into a healthy human host -> host never developed smallpox
Describe the major contribution of Pasteur.
If applicable, who is he known as?
disproved “spontaneous generation” (some forms of life could arise spontaneously from nonliving matter) and established the “theory of biogenesis” (living cells arise only from pre-existing living cells) which was later supported by Kochs “Germ Theory of Disease”
Compare and contrast the theories of Spontaneous Generation and Biogenesis.
Spontaneous generation: some forms of life could arise spontaneously from nonliving matter
Biogenesis: living cells arise only from pre-existing living cells
How did Pasteur disprove Spontaneous Generation?
At first, he poured clean broth into a long-necked flask, but later microorganisms were present in the broth (due to the straight neck)
He then used a S-shaped flask and boiled the broth. After the broth was cooled, microbes were still not present. This was because the bent flask prevented microbes from entering. This proved that forms of life could not arise spontaneously from nonliving matter.
Describe the major contribution of Lister.
If applicable, who is he known as?
- created idea of sterile surgery
- began using chemical solutions (antiseptics) to treat surgical wounds and kill microbes
- applied “Germ Theory of Disease” to medical procedures
- reduced number of surgical infections and deaths
Describe the Germ Theory
live pathogenic microbes can cause infectious diseases (with specific signs and symptoms)
Describe the major contribution of Koch.
If applicable, who is he known as?
- established the “Germ Theory” (infectious diseases are caused by living pathogens)
- discovered bacteria (bacillus anthracis) in cattle and sheep as cause of Anthrax
- established “Koch’s Postulates” (rules) which are steps relating a specific pathogen to a specific disease
Describe the major contribution of Ehrlich.
If applicable, who is he known as?
- developed concept of chemotherapy (drug therapy; drugs used to treat DZ) by discovering first chemical substance against Syphilis (STD)
- created term “magic bullet” (target-specific drug) to describe that a chemical substance can be made to selectively target and destroy a pathogen without harming the infected host
Describe the major contribution of Fleming.
If applicable, who is he known as?
- discovered first antibiotic, Penicillin (comes from fungal mold)
- discovered this by examining how contaminated culture plates with mold colonies inhibited growth of surrounding bacteria
Describe the major contribution of Marshall.
If applicable, who is he known as?
- proved that most peptic ulcers were caused by bacterium, Helicobacter pylori
- studies found causative link between H. Pylori and gastric cancer
H. Pylori -> peptic ulcers -> gastric cancer
Define EID, emerging infectious diseases
What are some EIDs currently prevalent in human population?
P = Pathogen
diseases that are new or changing and are increasing/have potential to increase in frequency in the near future
SARS-CoV-2 (P) -> COVID-19 (EID)
Zika Virus (P) -> Zika Virus Disease (EID)
West Nile Virus (P) -> West Nile Virus Encephalitis (EID)
Influenza Virus (P) -> Influenza (EID)
Name key factors that contribute to the emergence of EIDs.
Describe
F R N D C G
- Frequent gene mutation: harmless microbes can undergo changes in DNA that make them into harmful microbes (pathogen)
- Rapid urbanization: when soil becomes disturbed, pathogens become airborne
- Natural disasters: ex: earthquakes can cause power outages which can disrupt clean water facilities that require electricity to function (people may drink contaminated water)
- Developing drug resistance: pathogen no longer responds to drug
- Climate change: wet areas can become dry (vise versa) which can attract disease-carrying living things, thus introducing a disease that has never been seen in that area
- Global travel: quick transmission of pathogens
