Chap 1 Flashcards
Microorganisms
Organisms that are too small to be seen with the unaided eye
Types of microbes
1.Bacteria 2.fungi 3.protozoa 4.microscopic algae
5. viruses
Pathogenic
Disease producing
A ____ microbes are pathogenic
A Few microbes are pathogenic
Function of microbes in our lives
1.pathogenic
2.decompose organic waste
3. Generate O2 (photosynthesis)
4.Make ethanol, acetone and vitamins. (Chemical products)
5. Fermented foods. Vinegar, cheese, yogurt.
6. Make manufacturing & disease treatment products like cellulose and insulin
Why do people need knowledge of microorganisms?
1.Prevent food spoilage
2.prevent disease
3. understand causes and transmission of disease to prevent epidemics
Describe some of the destructive and beneficial actions of microbes
- Destructive: -pathogenic agents
- incorrectly fermented foods
2.beneficial
-insulin and other disease treatment products
-O2 production
-decomposition
Body cells in an adult human
30 trillion
How many bacterial cells in an adult human?
40 trillion
Microbiome
Group of microbes that live stably on/in the human body
Functions of the microbiome
1-Help maintain good health
2-Can prevent growth of pathogenic microbes
3-may help train immune system to discriminate threats
Normal microbiota
Collection of acquired microorganisms on or in a healthy human being
Normal microbiota begins to be acquired at which age
Newborn
Normal microbiota may colonize the body in which two ways?
Indefinitely or fleetingly
Transient microbiota
Colonizes the body fleetingly
Colonization can only occur at body sites that
Provide nutrients and the right environment for microbes to flourish
When did the human microbiome project begin
2007
What was the primary goal of the human microbiome project?
Determining the makeup of typical microbiota of various areas of the body
What was the secondary goal of the human microbiome project
Understanding relationship between changes in microbiome and human diseases
National microbiome initiative began in
2016
Purpose of the national microbiome initiative
Explores the role microbiomes play in different ecosystems
What percentage of all the cells in the human body are bacterial cells?
Unknown yet
Who established the system of scientific nomenclature in 1735?
Carolus Linnaeus
Parts of scientific names
1.Genus
2.specific epithet
How to distinguish scientific names?
Scientific names are italicized or underlined
Is capitalized
Genus
Is lowercase
Specific epithet
Are latinized and used worldwide
Scientific names
May be descriptive or honor a scientist
Scientific names
Escherichia coli honors
The discoverer Theodore escherich
Escherichia coli describes the bacterium’s habitat
The large intestine or colon
Staphylo-
Clustered
Coccus
Spherical
Aureus
Gold-colored
How may scientific names be abbreviated?
With the first letter of the genus and the specific epithet.
E. Coli
S. Aureus
E. Coli is found in the
Large intestine
S. Aureus is found on
The skin
Distinguish genus from a specific epithet
Genus is the first part, specific epithet is the second part.
Types of microorganisms
1.Bacteria
2.Archaea
3.Fungi
4.Protozoa
5.Algae
6.Viruses
7.Multicellular Animal Parasites
A cluster of rod-shaped cells. Scale bar indicates 3 micrometers which is about the length of one of the cells. SEM
A.H. influenzae.
A cluster of sporangia resembles balls on sticks. Scale bar is 50 micrometers which appears about three times the length of one of the sporangia heads (balls). SEM.
B. Mucor.
An amoeba has a blob-like shape with extensions called pseudopods approaching a food particle. Scale bar indicates 50 micrometers which is roughly half the length of the amoeba. SEM.
C. Amoeba.
Volvox resembles a large sphere composed of equally spaced small green dots. This larger sphere is partially filled with smaller oval shaped structures composed of tightly clustered dark green dots. Some of the oval structures overlap. Scale bar indicates 300 micrometers about the diameter of one of the dark green ovals within the larger structure. LM.
D. Volvox
A nerve cell is shown in grains surrounded by smaller red grainy patches of the zika virus. Zlkv. Scale bar indicates 70 nanometers, with the virus patches about 100 nanometers in diameter. TEM
Nerve cell
Prokaryotes
“prenucleus”
Bacteria: prokaryotes vs eukaryotes
Prokaryotes
How many cells do bacteria have?
One, bacteria are single-celled organisms.
The cell walls of bacteria are made of
Peptidoglycan
Bacteria divide via
Binary fission
Bacteria derive nutrition from
organic or inorganic chemicals or photosynthesis
Bacteria may “swim” by using moving appendages called
flagella
Archaea: prokaryotes vs eukaryotes
prokaryotes
describe the walls of archaea
lack peptidoglycan cell walls. May lack cell wall entirely
Archaea often live in what kind of environments
extreme environments
Examples of archaea
1.Methanogens
2.Extreme halophiles
3.Extreme thermophiles
Generally not known to cause disease in humans
Archaea
Fungi: Eukaryote vs Prokaryote?
Eukaryote
Eukaryote
Eukaryotes are organisms whose cells contain a nucleus and other membrane-bound organelles
Prokaryotes
a microscopic single-celled organism that has neither a distinct nucleus with a membrane nor other specialized organelles. Prokaryotes include the bacteria and cyanobacteria
Distinct nucleus surrounding DNA genetic material
Eukaryotes
Describe the cell walls of fungi
chitin
How do fungi get nutrition?
Absorb organic chemicals for energy
Type of unicellular fungi
yeasts
Types of multicellular fungi
molds and mushrooms
Molds
masses of mycelia, which are composed of filaments called hyphae
Sporangia
structures in fungi that produce and contain spores
Protozoa: Prokaryotic vs Eukaryotic
Eukaryotic cells
how do protozoa get nutrition?
1.Absorb or ingest organic chemicals
2.Free-living or parasitic (derive nutrients from a living host)
3. some are photosynthetic
Protozoa may be mobile via
pseudopods, cilia or flagella
pseudopods
a temporary growth on a cell that allows it to be mobile, almost like a little foot.
free-living
An organism that is not dependent on another organism for survival
protozoa reproduction
reproduce sexually or asexually
Algae: Eukaryotic or Prokaryotic?
Eukaryotes
Describe the cell walls of algae
cellulose
Where is algae found?
Freshwater, saltwater, and soil
How does algae feed itself?
Uses photosynthesis for energy. Produces Oxygen and carbohydrates.
How does algae reproduce?
Sexual and Asexual reproduction possible
Example of algae
volvox
Acellular
viruses
What does the core of viruses contain?
RNA, DNA
The core of viruses is surrounded by
a protein coat
The protein coat of viruses may be enclosed in?
a lipid envelope
When can viruses replicate?
ONLY when they are in a living host cell
Outside of host, viruses are
inert
Example of virus
Zik V
Multicellular Animal Parasites: Eukaryotic vs Prokaryotic
Eukaryotes
Not strictly microorganisms
Multicellular animal parasites
multicellular animals
Multicellular animal parasites
Examples of multicellular animal parasites
Parasitic flatworms and roundworms
helminths
Parasitic flatworms and roundworms
Some microscopic stages in their life cycles
multicellular animal parasites
Which groups of microbes are prokaryotes?
Bacteria
Archaea
Which groups of microbes are Eukaryotes?
Fungi
Protozoa
Algae
Multicellular Animal Parasites
Who developed the classification of microorganisms?
Carl Woese in 1978
Three domains based on cellular organization
1.Bacteria
2.Archaea
3.Eukarya
Types of Eukarya
Protists
Fungi
Plants
Animals
Contributions of Robert Hooke in 1665
living things are composed of little boxes, or “cells”
What idea marked the beginning of cell theory?
All living things are composed of cells
Who observed the first microbes?
Anton Van Leeuwenhoek
When were the first microbes observed?
1623-1673
animacules
viewed through magnifying glass.
archaic term for microscopic organisms by Anton van Leeuwenhoek
What is cell theory?
scientific theory in biology that states that all living organisms are made up of cells, which are the basic unit of life and structure
Spontaneous generation:
the hypothesis that life arises from nonliving matter; a “vital force” is necessary for life
the hypothesis that life arises from nonliving matter; a “vital force” is necessary for life
spontaneous generation
Biogenesis
the hypothesis that living cells arise only from preexisting living cells
the hypothesis that living cells arise only from preexisting living cells
Biogenesis
From where did the maggots come?
In Francesco Redi’s experiment
From the fly eggs
What was the purpose of the sealed jars in Francesco Redi’s experiment?
The sealed jars did not allow air or anything else to come into contact with the decaying meat
What was the purpose of the jars covered with fine net?
to allow air but not flies to come into contact with meat.
Francesco Redi’s experiment supports which theory? Spontaneous generation or Biogenesis?
Biogenesis. The maggots did not appear spontaneously, instead they came from other living cells.
Who used early microscope to observe microbes?
Anton van van Leeuwenhoek
Explain John Needham’s experiment?
John Needham boiled broth to kill all living organisms and then burnt the end off to prevent air from getting in. However things grew in the broth. He concluded that Spontaneous generation was the reason for the growths.
Where did the microbes from John Needham’s experiment come from?
from microbes that weren’t killed during boiling or from improperly closing the bottle. He thought it was spontaneous generation
Explain Lazzaro Spallanzani’s experiment
Spallanzani recreated needham’s experiment and sealed the broth in a flask then boiled it. He observed no microbial growth even after days of his experiment. He concluded that spontaneous generation does NOT occur. Supports BIOGENESIS
When was the theory of biogenesis first established?
1858
Rudolf Virchow contribution
said that cells arise from pre-existing cells
Louis Pasteur contribution
1861:Microorganisms are present in air
Explain Louis Pasteur’s experiment
Nutrient broth was placed in s-shaped flasks that allowed air in, but prevented the spread of microbes into the broth. The nutrient broth that was not sealed experienced microbial growth. The nutrient broth that was heated and immediately sealed experienced no microbial growth. Supported BIOGENESIS
Why did Pasteur use S-shaped flasks?
to keep microbes out, but let air in. Neck trapped microbes.
Microorganisms originate in ___ or _______
air or fluids, not mystical forces.
What supported spontaneous generation?
maggots arising from dead bodies and soil
How was spontaneous generation disproved?
by the experiments of Redi,Pasteur and spananzalli. Life did not arise from air alone, but from microbes in the environment.
when was the golden age of microbiology?
1857-1914
Name some of the important discoveries made during the golden age of microbiology
-Relationship between microbes and disease
-immunity
-antimicrobial drugs
Who showed that microbes are responsible for fermentation?
Pasteur
Fermentation
microbial conversion of sugar to alcohol in the absence of air
also responsible for the spoilage of food and beverages
microbial growth
How is wine spoiled?
bacteria that uses the air spoils wine by turning it into vinegar. (acetic acid)
Pasteurization
application of a high heat for a short time to kill harmful bacteria in beverages.
How did Pasteur believe he could prevent wine from spoiling?
demonstrated that spoilage bacteria could be killed by heat that was not hot enough to evaporate the alcohol in wine.
Fermentation discovered by
Pasteur
Who disproved spontaneous generation?
Pasteur
Who created pasteurization?
Pasteur
Aseptic surgery
Lister
Germ theory of disease was discovered by
Koch
Neisseria gonorrhoeae discovered by
Neisser
Pure cultures discovered by
Koch
Yellow fever by
Finlay
Showed that a silkworm disease was caused by a fungus 1835
Agostino Bassi
showed that another silkworm disease was caused by a protozoan 1865
Pasteur
advocated handwashing to prevent transmission of puerperal fever from one obstetrical patient to another
1840s: Ignaz Semmelweis
1860s: Applying Pasteur’s work showing that microbes are in the air, can spoil food, and cause animal diseases, ______ _______ used a chemical antiseptic (phenol) to prevent surgical wound infections
Joseph Lister
Mycobacterium tuberculosis
Koch
Agar (solid) media
Hess
Vibrio cholerae
Koch
Phagocytosis
Metchnikoff
Gram staining procedure
gram
Escherichia coli
Escherich
1876: _______ _____ discovered that a bacterium causes anthrax and provided the experimental steps, Koch’s postulates, to demonstrate that a specific microbe causes a specific disease
Robert Koch, specific microbe causes a specific disease.
1st of Koch’s postulates
1.The microorganism must be present in all diseased individuals, but not in healthy individuals.
Petri dish
petri
clostridium tetani
Kitasato
Theory of immunity
Ehrlich
Diphtheria Antitoxin
von Bering
Sulfur cycle
Winogradsky
_______ _______ inoculated a person with cowpox virus, who was then immune to smallpox
Edward Jenner
is derived from the Latin word vacca, meaning cow
vaccination
immunity
protection against diseases
Summarize in your own words the germ theory of disease.
Germ theory explains how microorganisms cause infectious diseases. Specific pathogens are responsible for causing specific infectious diseases. Germs can be transferred from person to person through the air, contaminated food, water or physical contact.Once germs enter the body they can reproduce and cause ilnness by releasing toxins or damaging cells.
What is the importance of Koch’s postulates?
- explain the causes for diseases
- Can help identify the causes for specific diseases
- Can help us further understand the causes for certain diseases.
What is the significance of Jenner’s discovery?
- Development of vaccination
- Eradication of smallpox
- influence on modern vaccinology
- Improved public health
Chemotherapy
Treatment of disease with chemicals is called
Chemotherapeutic agents used to treat infectious disease can be
synthetic drugs or antibiotics
are chemicals produced by bacteria and fungi that inhibit or kill other microbes
antibiotics
antibiotics
are chemicals produced by bacteria and fungi that inhibit or kill other microbes
Quinine from tree bark was long used to treat
malaria
speculated about a “magic bullet” that could destroy a pathogen without harming the host
Paul Ehrlich
1910:Ehrlich developed
a synthetic arsenic drug, salvarsan, to treat syphilis
When were sulfonamides synthesized?
1930’s
who discovered the first antibiotic (by accident) 1928
Alexander Fleming observed that Penicillium fungus made an antibiotic, penicillin, that killed S. aureus
penicillin killed
S. aureus
When was Penicillin tested clinically and mass-produced
1940’s
Problems with Antimicrobial Chemicals
1.Overuse can lead to resistance
2. Some drugs can be toxic to humans
Which drugs can especially be toxic to humans?
antivirals
When was the third golden age of microbiology?
late 1980’s to present
What was Ehrlich’s “magic bullet”?
Elrich’s magic bullet had a targeted approach for killing pathogens. Salvarsan specifically attacked the syphilis-causing bacteria without harming the patient’s own cells. Diseases can be cured effectively by understanding the mechanisms of pathogens.
Bacteriology
Study of bacteria
Mycology
study of fungi
Parasitology
is the study of protozoa and parasitic worms
study of immunity
immunology
_______ and ________ are used to prevent and cure viral diseases
vaccines and interferons
A major advance in immunology occurred in 1933 when Rebecca Lancefield
Lancefield classified streptococci based on their cell wall components
rebecca lancefield contribution
discovered differences in the chemical composition of a polysaccharide in the cell walls of many pathogenic streptococci.
virology
study of viruses
discovered the cause of mosaic disease of tobacco to be a virus
Dmitri Iwanowski in 1892 and Wendell Stanley in 1935
have made it possible to study the structure of viruses in detail
Electron microscopes
Microbial genetics
the study of how microbes inherit traits
Molecular biology
the study of how D N A directs protein synthesis
Genomics
the study of an organism’s genes; has provided new tools for classifying microorganisms
D N A made from two different sources
In the 1960s, Paul Berg inserted animal D N A into bacterial D N A, and the bacteria produced an animal protein
Recombinant DNA
showed that genes encode a cell’s enzymes
1941: George Beadle and Edward Tatum
showed that D N A is the hereditary material
1944: Oswald Avery, Colin MacLeod, and Maclyn McCarty
proposed a model of D N A structure
1953: James Watson and Francis Crick
discovered the role of m R N A in protein synthesis
François Jacob and Jacques Monod 1961
Microbial Ecology
is the study of the relationship between microorganisms and their environment
Bacteria convert
carbon, oxygen, nitrogen, sulfur, and phosphorus into forms used by plants and animals
Sewage is ______ water
99.9%
Treatment of sewage removes undesirable components so water can be
released or reused
How do microbes help us recycle sewage water?
to convert left over liquid and organic materials into by-products such as carbon dioxide
What do bacteria do to organic matter in sewage?
Bacteria degrade organic matter in sewage
What do bacteria degrade or detoxify in sewage?
Bacteria degrade or detoxify pollutants such as oil and mercury
Microbes that are pathogenic to insects are alternatives to
chemical pesticides
Why are pathogenic microbes a better alternative to chemical pesticides
Prevent insect damage to agricultural crops and disease transmission
Bacillus thuringiensis infections are fatal in
many insects but harmless to animals and plants
Bacillus thuringiensis produces
protein crystals toxic to insects
The toxin gene has been inserted into some plants to confer insect resistance
Biotechnology
is the use of microbes for practical applications, such as producing foods and chemicals
Recombinant D N A technology
enables bacteria and fungi to produce a variety of proteins, vaccines, and enzymes
Missing or defective genes in human cells can be replaced in
Gene therapy
are used to protect crops from insects and from freezing
Genetically modified bacteria
Normal microbiota
Microbes normally present in and on the human body are called
Importance of normal microbiota
1.Normal microbiota prevent growth of pathogens
2.Normal microbiota produce growth factors such as vitamins B and K
Resistance
is the ability of the body to ward off disease
resistance factors include
skin, stomach acid, and antimicrobial chemicals
biofilms
1.Microbes attach to solid surfaces and grow into masses
2.They will grow on rocks, pipes, teeth, and medical implants
Why can biofilms be dangerous?
Biofilms can cause infections and are often resistant to antibiotics
When does disease happen?
When a pathogen invades a host and overcomes the host’s resistance, disease results
Emerging infectious diseases (E I D s):
new diseases and diseases increasing in incidence
When was zika virus discovered?
Virus discovered in 1947 in Uganda
Human epidemics in Micronesia 2007, then in French Polynesia and Brazil in 2013-2015
zika virus disease
How is zika spread?
Spread by bite of an infected Aedes mosquito; also transmitted by sexual contact
Effects of zika during pregnancy
Infection during pregnancy can result in severe birth defects
Middle East respiratory syndrome (M E R S) cause
Caused by Middle East respiratory syndrome coronavirus (M E R S- C o V)
MERS is common to
SARS
SARS
Severe acute respiratory syndrome
1,800 confirmed human cases and 630 deaths since 2014
MERS
Also known as swine flu
First detected in the United States in 2009
Declared a pandemic, or worldwide large-scale outbreak, by W H O in 2009
H1N1 influenza
Influenza A virus
Primarily in waterfowl and poultry
Sustained human-to-human transmission has not yet occurred
Avian influenza A (H 5 N 1)
MRSA
1950s: Penicillin resistance developed
1980s: Methicillin resistance
1990s: M R S A resistance to vancomycin reported
Methicillin-resistant Staphylococcus aureus (M R S A)
VISA
vancomycin-intermediate S. aureus
VRSA
vancomycin-resistant S. aureus
Ebola hemorrhagic fever (EHF)
Ebola virus
Causes fever, hemorrhaging, and blood clotting
How is EHF transmitted?
Transmitted via contact with infected blood or body fluids
First identified near Ebola River, Congo
2014 outbreak in Guinea; over 28,000 infected over 2 years, with 1/3 of those infected dead
Ebola hemorrhagic fever
Causes hemorrhagic fever similar to Ebola
First cases in laboratory workers in Europe who handled African green monkeys from Uganda
13 outbreaks identified in Africa between 1975 and 2016
Marburg virus
marburg virus
Causes hemorrhagic fever similar to Ebola
First cases in laboratory workers in Europe who handled African green monkeys from Uganda
13 outbreaks identified in Africa between 1975 and 2016
Involving 1 to 252 people, with 57% mortality
African fruit bats are the natural reservoir for the virus (and also suspected of being the reservoir for Ebola virus)
Marburg virus
Differentiate normal microbiota and infectious disease.
Why are biofilms important?
1.Biofilms can cause infections and are often resistant to antibiotics
2. Biofilms contribute to ecosystem functioning nutrient cycling and bioremediation
What factors contribute to the emergence of an infectious disease?
masses of mycelia, which are composed of filaments called hyphae
Molds
masses of mycelia, which are composed of filaments called hyphae
Molds
The current system of nomenclature for organisms was established by
Carolus Linnaeus
Scientific nomenclature assigns each organism two names the genus and the
Specific epithet
Archaea, often found in extreme environments are divided into
3 main groups:
-thermophiles
-methanogens
-halophiles
In 1978, Carl Woese devised a system of classification that groups organisms into the domains bacteria archaea and
Eukarya
Eukarya includes all of the following except
a)viruses
b) protists
c)fungi
d)plants
e)animals
Viruses
Robert koch
Proved that bacteria can cause disease
Who discovered penicillin
Alexander Fleming
Who discovered a chemotherapeutic agent against syphilis
Ehrlich
Who discovered the structure of DNA
Watson and crick
Robert Koch developed his postulates while identifying the cause of which disease?
Anthrax
Jenner conducted an experiment that eventually led to one of the following concepts
Vaccination smallpox vaccine
The process of using just enough heat to kill most (but not all) of the bacteria that cause spoilage in a beverage was developed by
Pasteur
Salvarsan was a drug to treat syphilis developed by
Ehrlich
Which of the following causes a wide range of human infections including pimples/ boils, pneumonia, food poisoning, and surgical wound infections?
Staphylococcus aureus
Which of the following is not an example of an emerging infectious disease
Malaria
Pandemic
Disease affecting a large number of individuals in a short period of time on a global scale
All of the following are natural human defenses against disease except
Interferon
penicillin
skin and mucous membranes
Penicillin
An example of hemorrhagic fever virus is
Ebola virus
Bacillus thuringiensis is used as
A natural insecticide
Bioremediation is the use of microbes
To clean up pollutants and toxic wastes
Biotechnology can best be defined as using living organisms to
Develop useful products
Gene therapy can be used to treat
Cystic fibrosis
Which element can only be converted by bacteria into a form that is available to plants and animals
Nitrogen
Who challenged the case for spontaneous generation with the concept of biogenesis
Virchow
Second of Koch’s postulates
2.The agent must be isolated and grown outside the host
Second of Koch’s postulates
2.The agent must be isolated and grown outside the host
Third of Koch’s postulates
3.When the agent is introduced to a healthy, susceptible host, the host must get the disease.
Fourth of Koch’s postulates
4.The same agent must be found in the diseased experimental host.
