Test 1 Study questions Flashcards
______ membranes allow some molecules to pass but not others
Selectively permeable
What occurs when motile bacteria is placed in an environment with a gradient of a chemical attractant? What behavior would be predicted?
The bacteria will both reduce tumbling frequency and increase run duration in the direction of the chemical
Flexible bacteria with a helical shape are called
spirochetes
What does the cytoplasmic membrane of bacteria do?
- It retains the cytoplasm and its contents
- It acts a selectively permeable barrier, allowing some molecules to pass while preventing the movement of others
- It is the major site of ATP synthesis in aerobes
Chemotaxis is a process by which bacteria do what?
Move toward an attractant or away from a repellent
Which of the following is not considered a macronutrient?
Cobalt
What would happen to the surface area and volume of a spherical cell if the diameter of the cell doubles?
The surface area will increase by a factor of 4, while the volume will increase by a factor of 8
How exactly is the assembly of the flagellar filament?
The flagellin protein monomers assemble from the base of the flagellum within the cell envelope
Are all vesicles produced by the same mechanism of transporting material between cells?
They are not produced by the same mechanism
Organisms that ignore oxygen and grow equally well in its presence or absence are called
Aerotolerant
For surface cultivation of microorganisms, a sulfated polymer called agar can be extracted from ____ and added to liquid media in order to cause it to solidify
algae
Which of the following are reasons for the decline in a cell numbers during the death phase?
- Depletion of nutrients
- Accumulation of toxic waste materials
3.Depletion of O2
Which of the following can be used to isolate pure cultures of bacteria from mixtures?
- Spread plates
- Streak plates
- Pour plates
A cell may enter a stationary phrase because of
- the depletion of an essential nutrient
- a lack of available oxygen
- the accumulation of toxic waste products
The growth rate of a given specifies of micoorganism is dependent on?
The composition of the medium in which it is grown
Obligate anaerobes are usually poisoned by molecular oxygen but may grown in aerobic habitats if associated with facultative anaerobes that use up all available oxygen
This is true
Most microorganism do not?
live in eutrophic environments
Is it true that the size and shape of a colony is not useful for identification of microorganisms because microorganisms produce colonies that are indistinguishable from one another?
That is false they can be useful for identification
What does binary fission do?
Divides one cell into two identical daughter cells
Who suggested that disease was caused by invisible living creatures?
Roman Philosopher Lucretius and Physician Girolamo Fracastoro
How would one define microbiology?
It would be defined by not only the organisms it studies but also the tools used to study them
What is the role of microbes in maintaining temperature on earth?
They convert CO2 to CH4 (methane) both are which are green house gases that regulate temperature
List the top three causes of death in the U.S.
Heart diseases, cancer, stroke
How did the role of microbes change over the last 100 years?
1.Over the last 100 years there has been the clean water act (H2O purification and sewage treatment)
2. Vaccine
3. Antibiotics (Alexander Fleming)
What are some of the major contributions to the science of microbiology?
- The Swan-neck flask experiment- disproved spontaneous generation (life arising from nonliving things)
- Germ theory disease- life comes from living, and disease comes from germs
- Developed Pasteurization - a low temp heating method to eliminate unwanted organisms in wine
Who were major contributors to the science of microbiology?
- Antony Van Leeuwenkhoek: Microscope guy
- Edward Jenner: a vaccine for smallpox
- Ignaz Semmel Weis: wash hands to give birth, not to transfer disease
4.Robert Koch: Koch’s postulate one microbe= one disease (still practiced today)-epitology of anthrax - John Snow- epidemiology
- Paul Enrich: chemotherapy
- Alexander Fleming: Antibiotics
What are the impact of microbes in the environment? What do they do?
- Flow of energy- recycle carbon, nitrogen, oxygen, and sulfur cycle (major recyclers)
- Primary producers- converts inorganic to organic (takes gas and accumulate mass)
- Regulation of temperature- greenhouse gases (make oxygen)
- Symbiosis- Live in close association
Define what a cell and a microbe is
1.A cell is a unit of life
2. Microbes are entities that cannot be seen with the eyes
What are the hallmarks of a cell?
1.Ability to self -replicate
2. Source of energy
3. Control of chemicals
4. Cell membrane
5. DNA
What is something Prions, Virions and Viruses have in common?
They are acellular meaning they are made of similar compounds of cells but are not included in the three domains so they don’t need hallmarks
What is a prion, virion and a virus?
- Prions are an infectious protein (i.e., made cow disease)
- Viroids are infectious RNA (plant pathogens)
- Viruses do not have a cell membrane, they cannot flow, they are made of proteins and nucleic acids (can be either RNA or DNA)
What are the effects of microbes in the ecosystem
- They can transform the geosphere
2.They can affect the climate by the production of CO2/N2/O2/CH4 - They participate in relationships with other organisms
- They are only a small fraction that cause diseases
What is different about microbes?
- They are the first living creatures on planet earth
- They are more diverse than plants and animals
3.They grow in every ecological niche on earth that has a source of liquid H2O
In what harsh conditions can microbes thrive in?
They can thrive in
1. Gut
2. Skin
3. Atmosphere
4. Soil
5. Ocean
6.sediment beneath seafloor
7. Can survive anywhere that has liquid water
8. Archaea are known to exist in extreme conditions
Where can human bacteria be found?
They can be found on
1. Skin
2. Mouth
3. Intestines
4. other places and begin to colonize body shortly after birth
Which domains are prokaryotes and which ones are eukaryotes? Viruses?
1.Bacteria (prokaryotes)
2. Archaea (prokaryotes)
3. Eukarya (Algae, fungi, protozoa, animal and plants)
What are the 5 kingdoms?
- Fungi
- Protozoa
- Animals
- Plants
- Monera (bacteria and archaea)
List membrane-bound organelles found in eukaryotes but not in prokaryotes?
Italian Francesco Stelluti observed that
bees and weevils contain microscopic observations of organisms
Who was credited with publishing the first drawings of microorganisms in the scientific literature?
Robert Hooke
Who built the first microscope prototype and used it?
Antony van Leeuwenkhoek
What is the golden age of microbiology?
The conflict and subsequent studies on the role played by microorganism in causing disease during the spontaneous generation study.
Who suggested that organic matter in these extracts contained a “vital force” that could confer the properties of life on nonliving matter?
John Needham
Who conducted the experiment involving a sealed glass flask containing water and seeds and placing water to boil for 45 minutes?
Lazaro Spallanzani
What is pasteurization?
A heating method to destroy undesirable microbes.
Who created ethanol from the fermentation of beet sugars?
M. Bigo with assistance from Pasteur.
Who constructed a porcelain filter
Charles Chamberland
Who used these porcelain filters to study tobacco mosaic disease?
Dimitri Ivanowski and Martinus Beijerinck
What extreme conditions can microbes thrive through?
