MIC 206 ASU Practical 1 Review Questions
with Verified Correct Answers
What types of nutrients are required for a microorganism to grow?
water, energy source, carbon source, nitrogen, minerals, vitamins
Nutrient - Water
Makes up ~80% of the cell
All enzymatic reactions and transport of materials occurs in its presence
Nutrient - Energy Source
All cells need ways to make ATP and carry out biosynthesis
Chemotrophs
Break chemical bonds to derive energy
Phototrophs
Energy derived from sunlight via photosynthetic pigments
Nutrient - Carbon Source
All cells are carbon based
Heterotrophs
Obtain organic carbon (carbohydrates, proteins, fats, DNA, amino acids)
Autotrophs
obtain carbon by fixing CO2
Nutrient - Nitrogen
,Essential element
DNA/RNA, amino acids, peptidoglycan
Nutrient - minerals
Metals and ions needed for metabolism (in small amounts)
Zinc, copper, iron, sulfur, and others (~30)
Nutrient - vitamins
Coenzymes for metabolism
NAD and Flavins
States of Media
Liquid, solid, semi-solid
Liquid Media
"Broth" inside of a test tube
Solid media
In a petri dish
Requires an agent to solidify
Agar ~[1.5%] (is similar to gelatin of Jell-O)
Semi-solid
Similar to solid (0.4%-1.0% of agar) ex: nutrient agar 0.4% (motile vs non-motile organism)
This will jiggle like Jell-O
Some contain Redox indicator like TCC (triphenyl tetrazolium chloride)
Media preparation
, Made of dehydrated powders (weighed out, add water, dissolve. pH may need adjustment
Sterilization
Performed in autoclaveA
Autoclave
Kills all microbes (cells, spores, and endospores)
-121 ºC
-15 psi
-15 minutes (more volume increases time)
media preparation
Always use aseptic technique
Pouring media
-media with agar = plates and slants
-media without agar = broths
Using Media in Lab
Always attempt to work with pure cultures
Look for contamination and water on plate surface
Types of Media
complex, defined, selective, differential
Complex Media
Exact chemical composition is unknown
Wide range of growth
Defined Media
with Verified Correct Answers
What types of nutrients are required for a microorganism to grow?
water, energy source, carbon source, nitrogen, minerals, vitamins
Nutrient - Water
Makes up ~80% of the cell
All enzymatic reactions and transport of materials occurs in its presence
Nutrient - Energy Source
All cells need ways to make ATP and carry out biosynthesis
Chemotrophs
Break chemical bonds to derive energy
Phototrophs
Energy derived from sunlight via photosynthetic pigments
Nutrient - Carbon Source
All cells are carbon based
Heterotrophs
Obtain organic carbon (carbohydrates, proteins, fats, DNA, amino acids)
Autotrophs
obtain carbon by fixing CO2
Nutrient - Nitrogen
,Essential element
DNA/RNA, amino acids, peptidoglycan
Nutrient - minerals
Metals and ions needed for metabolism (in small amounts)
Zinc, copper, iron, sulfur, and others (~30)
Nutrient - vitamins
Coenzymes for metabolism
NAD and Flavins
States of Media
Liquid, solid, semi-solid
Liquid Media
"Broth" inside of a test tube
Solid media
In a petri dish
Requires an agent to solidify
Agar ~[1.5%] (is similar to gelatin of Jell-O)
Semi-solid
Similar to solid (0.4%-1.0% of agar) ex: nutrient agar 0.4% (motile vs non-motile organism)
This will jiggle like Jell-O
Some contain Redox indicator like TCC (triphenyl tetrazolium chloride)
Media preparation
, Made of dehydrated powders (weighed out, add water, dissolve. pH may need adjustment
Sterilization
Performed in autoclaveA
Autoclave
Kills all microbes (cells, spores, and endospores)
-121 ºC
-15 psi
-15 minutes (more volume increases time)
media preparation
Always use aseptic technique
Pouring media
-media with agar = plates and slants
-media without agar = broths
Using Media in Lab
Always attempt to work with pure cultures
Look for contamination and water on plate surface
Types of Media
complex, defined, selective, differential
Complex Media
Exact chemical composition is unknown
Wide range of growth
Defined Media
