Microbiology: Test 1 (Chapters 1-6)
with correct answers 100%
What are macromolecules? What are examples and what are the subunits that make them up? - Correct
Answer a molecule containing a very large number of atoms, such as a protein.
- Examples:
- Polypeptides
- Nucleic acids (sub: DNA; RNA)
- Lipids (sub: diverse structures)
- Polysaccarides (sub: sugars)
What is the smallest unit of life? - Correct Answer cell
What is PCR? What is required in the mixture for the process to work? How are the cycles regulated? -
Correct Answer Polymerase Chain Reaction: used to amplify certain regions of DNA to create many DNA
copies.
- Required:
- Primers
- Taq polymerase enzyme
- Buffer
- Nucleotides (A,C,T,G)
- Template DNA
- Regulated: denaturing, annealing, and elongation. (cycle will repeat usually around 25-35 times)
Why are viruses considered non-living? - Correct Answer They cannot reproduce on their own; little to
no biochemical activity outside of host; they inert and nonreactive outside of host.
Who are Pasteur and Koch? What contribution did they have on microbiology? - Correct Answer -
Pasteur: disproved spontaneous generation theory in late 1800s.
- Koch: determined Bacillus anthraces and Myobacterium tuberculosis were the causes of anthrax and
tuberculosis. (this helped sheepherders and cattle ranchers avoid costly animal losses)
,What do bacteria look like? - Correct Answer - spherical (cocci)
- rod shaped (bacilli)
- comma shaped (vibrios)
- spiral (spirilla)
- pleomorphic (varied shape)
What is the function of cytoplasmic membrane? - Correct Answer to control the passage of substances
into and out of the cell.
What is peptidoglycan and what is it made up of? - Correct Answer subunit forming a matrix (similar to
chain like fence) it gives cell shape and protection from osmotic lysis/ mechanical forces.
- N- acetylmuramic acid (NAM)
- N- acetylglucosamine (NAG)
Who developed a method of separating microbes based on the cell wall composition? What is the order
of this procedure? - Correct Answer Hans Christian Gram.
- Gram negative: decolorized by alcohol, losing the color of the primary stain, purple. red or pink due to
retaining the counter staining dye called safranin.
- Gram positive: not decolorized by the alcohol and will remain purple; crystal violet in cell wall.
What is the purpose of flagella? What does it mean by "polar flagella" and "peritrichous flagella"?
Where does the energy needed to move flagella come from? - Correct Answer allow bacteria
movement; spiral, hollow, rigid, filaments extending from the cell surface.
- Polar: one or more flagella arising from one or both poles of the cell.
- peritrichous: flagella all around the cell.
* proton motive force
What is a chemotaxis? What do the terms chemoattractant and chemorepellent mean? - Correct Answer
the movement of a bacterial cell toward a chemical attractant.
- attractant: food source.
, - repellent: chemical trying to avoid.
What are examples of eukaryal microbes that affect humans? - Correct Answer fungi, protozoa, slime
molds, and algae.
How were we able to determine that Archaea should be put in a different domain? - Correct Answer
Phylogeny. Woese and Fox began these studies in the 1970s.
What is the difference between hypertonic, hypotonic, and isotonic solutions? How will the cell react
when placed in each? - Correct Answer - hypertonic: high salt; net water loss.
- hypotonic: low salt; net water gain.
- isotonic: equivalent salt; no net loss or gain of water.
What is a virus? What are the components that make up the virion structure? What does it mean to be
enveloped or naked? - Correct Answer nonliving but can infect living organisms; consists of nucleic acid
molecules in a protein coat.
- single or double DNA or RNA; protein shell (capsid) around genome composed of many capsomere
proteins; possible envelope; symmetry.
- Enveloped: has a plasma membrane surrounding the nucleocapsid.
- Naked: no plasma membrane.
What is an endpoint assay? What does it tell us? - Correct Answer enzyme based assay that measures
the amount of material by the quantity of a substance consumed or product formed over the course of a
reaction.
Be able to calculate the viable cell counts. You will need to know formula. - Correct Answer
Concentration = CFU/((dil.)(vol.))
0.1: # of digits
add to 10^-2
has to be positive
CFU=85
with correct answers 100%
What are macromolecules? What are examples and what are the subunits that make them up? - Correct
Answer a molecule containing a very large number of atoms, such as a protein.
- Examples:
- Polypeptides
- Nucleic acids (sub: DNA; RNA)
- Lipids (sub: diverse structures)
- Polysaccarides (sub: sugars)
What is the smallest unit of life? - Correct Answer cell
What is PCR? What is required in the mixture for the process to work? How are the cycles regulated? -
Correct Answer Polymerase Chain Reaction: used to amplify certain regions of DNA to create many DNA
copies.
- Required:
- Primers
- Taq polymerase enzyme
- Buffer
- Nucleotides (A,C,T,G)
- Template DNA
- Regulated: denaturing, annealing, and elongation. (cycle will repeat usually around 25-35 times)
Why are viruses considered non-living? - Correct Answer They cannot reproduce on their own; little to
no biochemical activity outside of host; they inert and nonreactive outside of host.
Who are Pasteur and Koch? What contribution did they have on microbiology? - Correct Answer -
Pasteur: disproved spontaneous generation theory in late 1800s.
- Koch: determined Bacillus anthraces and Myobacterium tuberculosis were the causes of anthrax and
tuberculosis. (this helped sheepherders and cattle ranchers avoid costly animal losses)
,What do bacteria look like? - Correct Answer - spherical (cocci)
- rod shaped (bacilli)
- comma shaped (vibrios)
- spiral (spirilla)
- pleomorphic (varied shape)
What is the function of cytoplasmic membrane? - Correct Answer to control the passage of substances
into and out of the cell.
What is peptidoglycan and what is it made up of? - Correct Answer subunit forming a matrix (similar to
chain like fence) it gives cell shape and protection from osmotic lysis/ mechanical forces.
- N- acetylmuramic acid (NAM)
- N- acetylglucosamine (NAG)
Who developed a method of separating microbes based on the cell wall composition? What is the order
of this procedure? - Correct Answer Hans Christian Gram.
- Gram negative: decolorized by alcohol, losing the color of the primary stain, purple. red or pink due to
retaining the counter staining dye called safranin.
- Gram positive: not decolorized by the alcohol and will remain purple; crystal violet in cell wall.
What is the purpose of flagella? What does it mean by "polar flagella" and "peritrichous flagella"?
Where does the energy needed to move flagella come from? - Correct Answer allow bacteria
movement; spiral, hollow, rigid, filaments extending from the cell surface.
- Polar: one or more flagella arising from one or both poles of the cell.
- peritrichous: flagella all around the cell.
* proton motive force
What is a chemotaxis? What do the terms chemoattractant and chemorepellent mean? - Correct Answer
the movement of a bacterial cell toward a chemical attractant.
- attractant: food source.
, - repellent: chemical trying to avoid.
What are examples of eukaryal microbes that affect humans? - Correct Answer fungi, protozoa, slime
molds, and algae.
How were we able to determine that Archaea should be put in a different domain? - Correct Answer
Phylogeny. Woese and Fox began these studies in the 1970s.
What is the difference between hypertonic, hypotonic, and isotonic solutions? How will the cell react
when placed in each? - Correct Answer - hypertonic: high salt; net water loss.
- hypotonic: low salt; net water gain.
- isotonic: equivalent salt; no net loss or gain of water.
What is a virus? What are the components that make up the virion structure? What does it mean to be
enveloped or naked? - Correct Answer nonliving but can infect living organisms; consists of nucleic acid
molecules in a protein coat.
- single or double DNA or RNA; protein shell (capsid) around genome composed of many capsomere
proteins; possible envelope; symmetry.
- Enveloped: has a plasma membrane surrounding the nucleocapsid.
- Naked: no plasma membrane.
What is an endpoint assay? What does it tell us? - Correct Answer enzyme based assay that measures
the amount of material by the quantity of a substance consumed or product formed over the course of a
reaction.
Be able to calculate the viable cell counts. You will need to know formula. - Correct Answer
Concentration = CFU/((dil.)(vol.))
0.1: # of digits
add to 10^-2
has to be positive
CFU=85
