Microbiology 303 Exam test quiz and
answers graded A+
Metabolism - ANS✅✅Sum of all biochemical reactions that occur in a cell
Cultured Based Methods - ANS✅✅Grow microbes in the lab and examine their physiological traits
How do you grow microbes? - ANS✅✅Complex (Rich) Medium
Enrichment Medium
Selective Medium
Single Cell Isolation
Complex (Rich) Medium - ANS✅✅Fastest growing, best adapted to those conditions
No Targeted Selection
Many Microbes can grow
Ex. yeast extract, beef heart etc.
Best Adaptive organisms will grow first
No Dormant Cells - ANS✅✅Viable but non-culturable
organisms that cant grow on a rich medium
Most Organism in nature are Dormant
Culture less than 1% of all microbes
1% of Culturable Microorganism - ANS✅✅Cultures that we can gain in a lab:
,Live in similar conditions
Found in human bodies
disease
Enrichment Medium - ANS✅✅Medium that favors the growth of a targets microbe (usually
fastidious)
ex. blood agar or chocolate microbes
Lyses Blood Cells
Fastidious - ANS✅✅Requires extra nutrients to grow
Don't synthesis things need to survive
Live close to host
Selective Medium - ANS✅✅Target microbe growth, non-targeted microbes are killed or inhibited
Pros:
Select Desired metabolic capacity
Cons:
Only get certain types and you have KNOW what you are looking for
Chrome Agar - ANS✅✅Differentiates between pathogens because each organisms has a different
color.
Synthetic substrate
Differential Medium - ANS✅✅Distinguishes groups of microbes on the sample.
Flow Cytometry - ANS✅✅Florescence-activated cell sorting
,Selects out single cells for analysis of growth
Sorts for cell types - collection vessels etc.
How do you study metabolism? - ANS✅✅Studying nutritional requirements of a pure culture by
adding specific nutrient to culture medium
Bio-synthetic Capacity - ANS✅✅Capacity to synthesize whats necessary for itself to grow
Ex.
E. Coli is better than L. Mesenteriodes b/c
E. Coli doesn't require amino acids, vitamins etc.
It can create those things by itself
Measuring Cell Number - ANS✅✅Direct: Counting
cant tell if its alive or dead
requires a microscope
Indirect: Plating
Colony Forming Units (CFU)
Estimating:
Most Probably Number
- uses dilution to extinction
Light Scattering - turbidity
, Drawbacks:
A lot of excess requirements
- dilutions
- microbes difficulty growing
Direct Counts - ANS✅✅Viable Counts - LiveDead Strains
Measuring Turbidity - ANS✅✅Cloudy
Light Source and filter to sample the source
Used with Spectrometer
Optical Density (OD)
Growth Rate - ANS✅✅Measures the number of generations per time in log phase
Generation Time - ANS✅✅Time it takes to divide
generations per time
N = No2^n
N = final cell number
No = initial cell number
n = # of generations during period of exponential growth
Diauxic Growth - ANS✅✅Indicates that carbon source is used, cell adapts and synthesizes new
enzymes
Then utilizes another carbon source
Limitations to culture-based studies - ANS✅✅Most microbes cant be cultured
answers graded A+
Metabolism - ANS✅✅Sum of all biochemical reactions that occur in a cell
Cultured Based Methods - ANS✅✅Grow microbes in the lab and examine their physiological traits
How do you grow microbes? - ANS✅✅Complex (Rich) Medium
Enrichment Medium
Selective Medium
Single Cell Isolation
Complex (Rich) Medium - ANS✅✅Fastest growing, best adapted to those conditions
No Targeted Selection
Many Microbes can grow
Ex. yeast extract, beef heart etc.
Best Adaptive organisms will grow first
No Dormant Cells - ANS✅✅Viable but non-culturable
organisms that cant grow on a rich medium
Most Organism in nature are Dormant
Culture less than 1% of all microbes
1% of Culturable Microorganism - ANS✅✅Cultures that we can gain in a lab:
,Live in similar conditions
Found in human bodies
disease
Enrichment Medium - ANS✅✅Medium that favors the growth of a targets microbe (usually
fastidious)
ex. blood agar or chocolate microbes
Lyses Blood Cells
Fastidious - ANS✅✅Requires extra nutrients to grow
Don't synthesis things need to survive
Live close to host
Selective Medium - ANS✅✅Target microbe growth, non-targeted microbes are killed or inhibited
Pros:
Select Desired metabolic capacity
Cons:
Only get certain types and you have KNOW what you are looking for
Chrome Agar - ANS✅✅Differentiates between pathogens because each organisms has a different
color.
Synthetic substrate
Differential Medium - ANS✅✅Distinguishes groups of microbes on the sample.
Flow Cytometry - ANS✅✅Florescence-activated cell sorting
,Selects out single cells for analysis of growth
Sorts for cell types - collection vessels etc.
How do you study metabolism? - ANS✅✅Studying nutritional requirements of a pure culture by
adding specific nutrient to culture medium
Bio-synthetic Capacity - ANS✅✅Capacity to synthesize whats necessary for itself to grow
Ex.
E. Coli is better than L. Mesenteriodes b/c
E. Coli doesn't require amino acids, vitamins etc.
It can create those things by itself
Measuring Cell Number - ANS✅✅Direct: Counting
cant tell if its alive or dead
requires a microscope
Indirect: Plating
Colony Forming Units (CFU)
Estimating:
Most Probably Number
- uses dilution to extinction
Light Scattering - turbidity
, Drawbacks:
A lot of excess requirements
- dilutions
- microbes difficulty growing
Direct Counts - ANS✅✅Viable Counts - LiveDead Strains
Measuring Turbidity - ANS✅✅Cloudy
Light Source and filter to sample the source
Used with Spectrometer
Optical Density (OD)
Growth Rate - ANS✅✅Measures the number of generations per time in log phase
Generation Time - ANS✅✅Time it takes to divide
generations per time
N = No2^n
N = final cell number
No = initial cell number
n = # of generations during period of exponential growth
Diauxic Growth - ANS✅✅Indicates that carbon source is used, cell adapts and synthesizes new
enzymes
Then utilizes another carbon source
Limitations to culture-based studies - ANS✅✅Most microbes cant be cultured
