You are in browse mode. You must login to use MEMORY

level: Exam Q's

Questions and Answers List

level questions: Exam Q's

Question	Answer
The lowest number of a target microbe that can be detected by a method of analysis	Sensitivity
The lowest number of a target microbe that can be detected by a method of analysis	Sensitivity
An immune protein (immunoglobulin) produced in response to a foreign antigen entering the body	Antibodies
An immune protein (immunoglobulin) produced in response to a foreign antigen entering the body	Antibodies
Method of using specific antibodies to differentiate various serotypes within a species	serotyping
A group of laboratories that fingerprint pathogens linked to foodborne disease outbreaks	PulseNet
Can be used to reliably detect Staphylococcus aureus in foods	Thermostable Nuclease
This word refers to the lipopolysaccharide layer of Gram-negative bacteria	endotoxin
A statistical based cultural method for estimating the number of coliforms in a water sample	Most Probable Number
Enzymes that can be used to label antibodies for ease of detection of target antigens	Peroxidase alkaline phosphatase, B galactosidase
Resistance to the flow of an alternating electric current through a medium	Impedance
A solution used to dissolve calcium alginate swab	sodium hexametaphosphate
A dye that stains DNA and mRNA	propidium iodide / acridine orange
The clinical isolate (pathogen) matches the food isolate in a foodborne disease investigation	epidemiological link
Genes that code for the luciferase enzyme	Luciferin
A subunit of the bacterial ribosome that is highly conserved (slow rate of evolution)	16S subunit
A chemical method used to detect endotoxin	Limulus Amoebocyte Lysate (LAL)
A short piece of ssDNA that provides a starting point for DNA synthesis in PCR	Primer
Can be used to bind antibodies to increase visibility of antibody and antigen agglutination	Agglutination test
An immune protein (immunoglobulin) produced in response to a foreign antigen entering the body	Antibodies
The lowest number of a target microbe that can be detected by a method of analysis	Sensitivity
Antimicrobial present in egg white	Phosvitin
Antimicrobial present in egg yolk	Lysozyme and ovotransferrin (conalbumin)
Microbial group (bacteria, molds, or yeast?) than can grow over a wide pH range (1.5-9)	Molds
(T/F) Visibility of antiobody/antigen reaction is improved by using antibodies attached to polystyrene beads	True
(T/F) The Taq polymerase enzyme exhibits optimal activity at about 70-75 C	True
(T/F) RNA restriction endonuclease can be used to convert RNA to cDNA	False, the enzyme to do that would be reverse transcriptase
(T/F) Binding of specific antibodies with antigens on microbial cells can result in visible agglutination	True
(T/F) moderate heating or low pH can separate DNA strands	False, high heat or high pH
(T/F) each cycle of the PCR quadruples the amount of target DNA	False, doubles
(T/F) DNA fragments are positively charged and migrate through the agarose gel towards the negative electrode	False, fragments are negatively charged and move towards the positive anode
(T/F) a reaction mixture temperature of 55 C is ideal for the primer annealing step of PCR	True
(T/F) In detecting microbe using flow cytometry, the excitation spectrum of the dye must match the wavelength of the laser beam (detector)	True
(T/F) Irrespective of the physiological state of the bacterial cell, the ATP content remains relatively constant	False
(T/F) the Limulus Amoebocyte Lysate (LAL) detects both viable and non-viable gram positive bacteria	True
(T/F) DNA restriction endonucleases cut DNA at specific points to give DNA fragments	True
(T/F) Yeast cells contain about 100 times more ATP than bacterial cells	True
(T/F) In whole genome sequencing only the important target segments of the whole genome are sequenced	False
(T/F) The enzyme used in PCR (Taq polymerase) exhibits optimal activity at about 70-75 C	True
Name the enzyme used in PCR and list 3 major characteristics	Taq Polymerase - heat resistant - very few errors - highly efficient activity
List the PCR reaction components and the function of each component (5 total)	Target DNA: DNA you want to amplify Primer: anneals to SSNDA, provides starting point for Taq polymerase Nucleotides: building blocks for DNA Taq Polymerase: extends primer to copy the DNA Buffer solution: maintains pH for enzymatic activity
List the three components of the buffered ATP test solution that must be present to produce light (luminescence) for a positive ATP test reuslt. Clearly state the role of each component.	Luciferin: Luciferase: ATP:
Name and give components of a natural antimicrobial system in raw milk. Give advice to farmers w/o refrigeration to avoid spoilage.	Lactoperoxidase antimicrobial system --> Lactoperoxidase, thyocya??, hydrogen peroxide 1. add
Describe PCR, ELISA step by step and include diagram	...
Describe procedure for Pule electric field electrophoresis and whole genome sequencing	...