MCB2010 - Exam 2 Questions with Complete Solutions 100% Solved| Grade A+
Maximum Growth Temperature Highest temperature at which an organism is able to
conduct metabolic functions
Optimal Growth Temperature The temperature at which the metabolic activity of the
organisms produces the greatest rate of growth
Psychrophile Grow best below 59F; do not cause disease in humans
Psychrotroph Grow best from 45F-95F; can infect humans and produce disease; these
microbes when placed in a fridge, will reproduce, and grow in number
Mesophile Grow best from 68F-108F; what most human pathogens are
Thermophile Grow at above 113F; do not cause disease in humans
Hyperthermophile Grow best above 176F; do not cause disease in humans
Acidophile Grow best in acidic environments
Acid Tolerant Prefer neutral pH, but can temporarily survive in an acidic environment
Alkinophiles Grow best in alkaline environments
Neutrophiles Prefer a neutral pH
What is a Biofilm? Why are Biofilms problematic to the Medical Community? A complex
relationship of numerous organisms, often different species, that bind together on a surface
,and often exhibit new functionality than they did as a single microorganism. Responsible for
nosocomial disease via catheters, endotracheal tubes, etc.
What is Binary Fission? How most prokaryotes reproduce; process where a cell doubles in
number and then divides in half producing two daughter cells
What is Generation Time? The time it takes for a cell to double in number
Binary fission Cell replicates its chromosome (DNA) and both chromosomes attach to the
cytoplasmic membranes on separate sides
Cell elongates and forms a new plasma membrane and wall
Cell wall complete. Cells separate and process repeats anew
Bacteria Growth Curve: Lag Phase Bacteria adjusting to environment; minimal increase in
cell number
Bacteria Growth Curve: Log (Exponential) Phase Maximum rate of growth for organism; best
time to start an antibiotic
Bacteria Growth Curve: Stationary Phase Number of cells remain constant
Bacteria Growth Curve: Death Phase Cells die off at an exponential rate
Disinfection The use of physical or chemical agents (disinfectants) to destroy microbes; does
NOT kill all pathogens
Sterilization The removal or destruction of ALL microbes (viruses, bacteria, NOT PRIONS)
, Aseptic Environment/procedure that is free of contamination of pathogens
Degerming Removal of microbes from a surface through the process of scrubbing
Pasteurization Process of heating a food/drink just enough to reduce the number of
microbes but not affect the products quality
Sanitization Disinfecting places and utensils used by the public to reduce the number of
pathogenic microbes to meet public health standards
-cide/cidal Agent that destroys or permanently inactivates a microbe
-static Agent inhibits microbial metabolism and growth; does not kill microbes
Agents which interrupt cell walls/membranes If the cell wall or cell membrane is destroyed,
the cell will die
Agents which interrupt cell metabolism If proteins are denatured, it will lose all
metabolic/structural processes; if nucleic acids (proteins) are destroyed protein synthesis will
be ceased
Antimicrobial Agents: High Level Sterilizes all pathogens including endospores
Antimicrobial Agents: Intermediate Level Used to disinfect noninvasive medical instruments
Antimicrobial Agents: Low Level Used to disinfect items that only contact the skin
Maximum Growth Temperature Highest temperature at which an organism is able to
conduct metabolic functions
Optimal Growth Temperature The temperature at which the metabolic activity of the
organisms produces the greatest rate of growth
Psychrophile Grow best below 59F; do not cause disease in humans
Psychrotroph Grow best from 45F-95F; can infect humans and produce disease; these
microbes when placed in a fridge, will reproduce, and grow in number
Mesophile Grow best from 68F-108F; what most human pathogens are
Thermophile Grow at above 113F; do not cause disease in humans
Hyperthermophile Grow best above 176F; do not cause disease in humans
Acidophile Grow best in acidic environments
Acid Tolerant Prefer neutral pH, but can temporarily survive in an acidic environment
Alkinophiles Grow best in alkaline environments
Neutrophiles Prefer a neutral pH
What is a Biofilm? Why are Biofilms problematic to the Medical Community? A complex
relationship of numerous organisms, often different species, that bind together on a surface
,and often exhibit new functionality than they did as a single microorganism. Responsible for
nosocomial disease via catheters, endotracheal tubes, etc.
What is Binary Fission? How most prokaryotes reproduce; process where a cell doubles in
number and then divides in half producing two daughter cells
What is Generation Time? The time it takes for a cell to double in number
Binary fission Cell replicates its chromosome (DNA) and both chromosomes attach to the
cytoplasmic membranes on separate sides
Cell elongates and forms a new plasma membrane and wall
Cell wall complete. Cells separate and process repeats anew
Bacteria Growth Curve: Lag Phase Bacteria adjusting to environment; minimal increase in
cell number
Bacteria Growth Curve: Log (Exponential) Phase Maximum rate of growth for organism; best
time to start an antibiotic
Bacteria Growth Curve: Stationary Phase Number of cells remain constant
Bacteria Growth Curve: Death Phase Cells die off at an exponential rate
Disinfection The use of physical or chemical agents (disinfectants) to destroy microbes; does
NOT kill all pathogens
Sterilization The removal or destruction of ALL microbes (viruses, bacteria, NOT PRIONS)
, Aseptic Environment/procedure that is free of contamination of pathogens
Degerming Removal of microbes from a surface through the process of scrubbing
Pasteurization Process of heating a food/drink just enough to reduce the number of
microbes but not affect the products quality
Sanitization Disinfecting places and utensils used by the public to reduce the number of
pathogenic microbes to meet public health standards
-cide/cidal Agent that destroys or permanently inactivates a microbe
-static Agent inhibits microbial metabolism and growth; does not kill microbes
Agents which interrupt cell walls/membranes If the cell wall or cell membrane is destroyed,
the cell will die
Agents which interrupt cell metabolism If proteins are denatured, it will lose all
metabolic/structural processes; if nucleic acids (proteins) are destroyed protein synthesis will
be ceased
Antimicrobial Agents: High Level Sterilizes all pathogens including endospores
Antimicrobial Agents: Intermediate Level Used to disinfect noninvasive medical instruments
Antimicrobial Agents: Low Level Used to disinfect items that only contact the skin
