MBIO 3401 EXAM QUESTIONS AND ANSWERS |
WITH COMPLETE SOLUTION
In the history of classification of microbes, who were the key historical contributors and
what were their key contributions?
Leeuwenhoek- an early microscopist, father of micro.
Robert hooke - built the first compound microscope
Robert koch - german physician & founder of the scientific method of microbiology ( the chain
of infection, or transmission of a disease
Leeuwenhoek
an early microscopist, father of micro.
Robert hooke
built the first compound microscope and coined the term cell
Robert koch
German physician and founder of the scientific method of microbiology ( the chain of infection,
or transmission of a disease)
Francesco redi
showed that maggots in decaying meat were the offspring of flies
Lazzaro spallanzani
showed that a sealed flask of meath broth sterilized by boiling failed to grow microbes
Louis pasteur
,began as an organic chemist
Discovered the microbial basis of fermentation
Globally where are microbes able to grow and not grow?
"normal growth"
- sea level
- temperature 20 C - 40 C
- near - neutral pH (7)
- Ample nutrients -> Can grow anywhere with proper nutrition
any biological niche outside of this is considered "extreme"
What are the typical size ranges of each major type of microbe?
Bacteria are typically 0.2-2µm
Eukaryotic microbes are 2µm-20cm
Prokaryotes 0.4µm
What is the size of E. coli?
2µm (micrometers) or 2*10^-6 m
What microscopes most easily visualize moving flagella?
Using dark-field microscopy by Macnab and Ornston
dark field optics study the bacterial motility
, What number of starting cells would produce any given number of final cells in log phase
growth after a specific number of generations?
log Nt = logN0 + nlog2
How is glucose transported into cells occur when energy sources (ATP/PEP etc) are not
available?
Glucose uniporter or non dependent glucose symporter
Passive transport does not require energy
When and how can oxygen be toxic to cells, and how do cells mediate this toxicity?
Certain reactions can destroy the ROS (reactive oxygen species).
Catalase, peroxidase, FAD
Aerobes require enzymes to destroy ROS; the production of ROS often begins with FAD moving
an electron to O2
What is the starvation response of cells?
“Programmed cell death” Some bacterial populations will sacrifice themselves to save others;
they give their nutrients to other bacteria in the population
One of the mechanisms used: is toxin-antitoxin systems (TA).
How are petri plates sterilized before we use them?
steam autoclaving
Why don't bacteria grow in concentrated sugar solutions?
WITH COMPLETE SOLUTION
In the history of classification of microbes, who were the key historical contributors and
what were their key contributions?
Leeuwenhoek- an early microscopist, father of micro.
Robert hooke - built the first compound microscope
Robert koch - german physician & founder of the scientific method of microbiology ( the chain
of infection, or transmission of a disease
Leeuwenhoek
an early microscopist, father of micro.
Robert hooke
built the first compound microscope and coined the term cell
Robert koch
German physician and founder of the scientific method of microbiology ( the chain of infection,
or transmission of a disease)
Francesco redi
showed that maggots in decaying meat were the offspring of flies
Lazzaro spallanzani
showed that a sealed flask of meath broth sterilized by boiling failed to grow microbes
Louis pasteur
,began as an organic chemist
Discovered the microbial basis of fermentation
Globally where are microbes able to grow and not grow?
"normal growth"
- sea level
- temperature 20 C - 40 C
- near - neutral pH (7)
- Ample nutrients -> Can grow anywhere with proper nutrition
any biological niche outside of this is considered "extreme"
What are the typical size ranges of each major type of microbe?
Bacteria are typically 0.2-2µm
Eukaryotic microbes are 2µm-20cm
Prokaryotes 0.4µm
What is the size of E. coli?
2µm (micrometers) or 2*10^-6 m
What microscopes most easily visualize moving flagella?
Using dark-field microscopy by Macnab and Ornston
dark field optics study the bacterial motility
, What number of starting cells would produce any given number of final cells in log phase
growth after a specific number of generations?
log Nt = logN0 + nlog2
How is glucose transported into cells occur when energy sources (ATP/PEP etc) are not
available?
Glucose uniporter or non dependent glucose symporter
Passive transport does not require energy
When and how can oxygen be toxic to cells, and how do cells mediate this toxicity?
Certain reactions can destroy the ROS (reactive oxygen species).
Catalase, peroxidase, FAD
Aerobes require enzymes to destroy ROS; the production of ROS often begins with FAD moving
an electron to O2
What is the starvation response of cells?
“Programmed cell death” Some bacterial populations will sacrifice themselves to save others;
they give their nutrients to other bacteria in the population
One of the mechanisms used: is toxin-antitoxin systems (TA).
How are petri plates sterilized before we use them?
steam autoclaving
Why don't bacteria grow in concentrated sugar solutions?
