LSU BIOL 2051 Lab Midterm
Experiment 7 Questions and Answers.
An individual's ___ and ___ are the key determinants for physical characteristics of an organism.
- Answer genetics; environment
___ have the metabolic pathway to synthesize a red-colored pigment call prodigiosin at room
temperature. - Answer Serratia marcescens
True or false?: Not every organism has an environment at which is grows best. - Answer
False; every organism does
Benefit of low temperature?
Benefit of high temperature? - Answer low: acts as food preservative
high: reduces microbial load in food
What is the limitation of UV radiation? - Answer penetrates poorly so it has limited
application for eliminating microbes
pH control is widespread in where? - Answer food industry
cleaning products
establishment of normal flora on different parts of body
What can salt do when it comes to food? - Answer control the growth of microorganisms on
food
What particular food can salt control growth on? - Answer fish and game
Who lead to the discovery of pasteurization? How? - Answer Pasteur; by discovering that
grape juice could be sterilized by heating
Pasteurization - Answer gentle heating used to eliminate organisms that can cause spoilage
in food products
What is rice easily contaminated with? Why? - Answer Bacillus; it's contaminated by Bacillus
species because it how it's grown despite being prepared with boiling water
, Why can Bacillus species withstand boiling water? - Answer they form endospores
Thermophiles - Answer grow at high temperatures (45-80 C)
optimum growth at 80 C
Mesophiles - Answer grow well at human body temperature (20-45 C)
optimum growth at 37 C
Psychrophiles - Answer grow at low temperatures (under 20 C)
All microbes have a(n) ___ over which they grow and a(n) ___ at which they grow best. - Answer
range of temperatures; optimum temperature
What happens when temperatures exceed the optimum temperature? - Answer enzymes
become denatured
cell membrane and nucleic acids destroyed
organism may die
What happens when temperature drop below the optimum temperature? - Answer rate of
cellular enzyme activity diminishes
lipids in cell membrane begin to solidify
membrane function impaired
growth inhibited
What is the difference between the cell's temperature falling below or above optimum
temperature? - Answer above is when the cell is most likely to die
below may not kill the cell
What type of sunlight is ultraviolet radiation?q - Answer the portion of sunlight that is
normally screened by the ozone layer
Is UV Radiation harmful to humans? If so, how? - Answer yes it's lethal because it can be
readily absorbed by nucleic acids, cause thymine dimers to form in DNA
UV radiation leads to ___ and/or ___ in human cells. - Answer mutations; death
Experiment 7 Questions and Answers.
An individual's ___ and ___ are the key determinants for physical characteristics of an organism.
- Answer genetics; environment
___ have the metabolic pathway to synthesize a red-colored pigment call prodigiosin at room
temperature. - Answer Serratia marcescens
True or false?: Not every organism has an environment at which is grows best. - Answer
False; every organism does
Benefit of low temperature?
Benefit of high temperature? - Answer low: acts as food preservative
high: reduces microbial load in food
What is the limitation of UV radiation? - Answer penetrates poorly so it has limited
application for eliminating microbes
pH control is widespread in where? - Answer food industry
cleaning products
establishment of normal flora on different parts of body
What can salt do when it comes to food? - Answer control the growth of microorganisms on
food
What particular food can salt control growth on? - Answer fish and game
Who lead to the discovery of pasteurization? How? - Answer Pasteur; by discovering that
grape juice could be sterilized by heating
Pasteurization - Answer gentle heating used to eliminate organisms that can cause spoilage
in food products
What is rice easily contaminated with? Why? - Answer Bacillus; it's contaminated by Bacillus
species because it how it's grown despite being prepared with boiling water
, Why can Bacillus species withstand boiling water? - Answer they form endospores
Thermophiles - Answer grow at high temperatures (45-80 C)
optimum growth at 80 C
Mesophiles - Answer grow well at human body temperature (20-45 C)
optimum growth at 37 C
Psychrophiles - Answer grow at low temperatures (under 20 C)
All microbes have a(n) ___ over which they grow and a(n) ___ at which they grow best. - Answer
range of temperatures; optimum temperature
What happens when temperatures exceed the optimum temperature? - Answer enzymes
become denatured
cell membrane and nucleic acids destroyed
organism may die
What happens when temperature drop below the optimum temperature? - Answer rate of
cellular enzyme activity diminishes
lipids in cell membrane begin to solidify
membrane function impaired
growth inhibited
What is the difference between the cell's temperature falling below or above optimum
temperature? - Answer above is when the cell is most likely to die
below may not kill the cell
What type of sunlight is ultraviolet radiation?q - Answer the portion of sunlight that is
normally screened by the ozone layer
Is UV Radiation harmful to humans? If so, how? - Answer yes it's lethal because it can be
readily absorbed by nucleic acids, cause thymine dimers to form in DNA
UV radiation leads to ___ and/or ___ in human cells. - Answer mutations; death
