Viruses and Prions
What is the role of a capsid for a virus?
Protects the viral genome from damage
What is the pairing of the nitrogenous bases?
Adenine with thymine (uracil)
Cytosine with guanine
What is the goal of gene therapy
replace defective genes with working copies
What is the difference between "-cide" and "-static"
"-cide": kills
"-static": inhibits growth
What is the therapeutic index
compares the toxic does to the minimum effective dose
How are prions transmitted and why are they so deadly?
Enters the body, begins misfolding your own proteins
Describe the three parts of transcription
Initiation: RNA polymerase binds to template strand
Elongation:RNA polymerase binds to complementary RNA strand in a 5' to 3' orientation
Termination: RNA polymerase recognizes stop, releasing the mRNA strand
What is the difference between indirect ELISA and direct ELISA
Indirect: tests for antibodies
Direct: tests for antigen
Phenols, alcohols, detergents, aldehydes, and halogens are examples of what?
Chemical control
What is a superinfection? give an example
Caused after the destruction of microbes from a different infection, leading to another one ie. Yeast infection and C. diff
What are the three capsid shapes?
helical, icosahedral, and complex
Describe translation
mRNA binds to rRNA, tRNA with the corresponding anticodon to the codon brings the correct amino acid. Begins forming a polypeptide chain, when stop codon is reached it releases the polypeptide chain, creating a protein
What are the three methods for identifying a specimen? describe them
Phenotypic: cell morphology, physiology, and biochemistry
Genotypic: genetic techniques
Immunologic: Serological analysis
What are the two examples of mechanical barriers
HEPA filters and N95 Masks
Describe a Kirby-Bauer and E-test
Kirby-Bauer: bacteria on a plate with disks of an antimicrobial drug, measure zone of inhibition
E-Test: determines minimum inhibitory concentration
Describe the viral life cycle (each part and whats occuring)
Attachment: virus binds to receptors
Entry: virus enters the host cell
Replication: virus makes copies of its own components
Assembly: virus assembles its components into virions
Release: virus leaves cell to infect others
Describe missense mutation, nonsense mutation, silent mutation, and a frameshift mutation
Missense: changes to a different amino acid
Nonsense: changes to a stop codon
Silent: doesn't change amino acid
Frameshift: changes reading frame through addition or deletion
What cuts DNA at sites with a particular nucleotide sequence
Restriction endonuscleases
Describe the differences between sterilization, disinfection, sanitization, and antisepsis
sterilization: kills all microbes present
Disinfection: kills disease causing microbes
Sanitization: reduces microbes to safe level
Antisepsis: kills or inhibits microbes on living tissue
What is used to treat MERSA? why?
vancomycin, MRSA has the MecA gene, changes the binding site to penicillin cannot bind
Describe the 4 infection kinetics (the graphs) and give examples of each
Acute: host gets infected but virus is cleared (flue)
Persistant: host gets infected, but virus is never cleared (stays at low levels) (HIV)
Latent: host gets infected, virus is mostly cleared, but then gets reactivated (shingles)
Cancer: virus immortalizes cells, leading to cancer
Describe DNA replication, what is going on?
Helicase breaks the hydrogen bonds of DNA, making the fork, Primase adds RNA primer, DNA polymerase III makes leading strand and lagging strand, DNA Polymerase I replaces RNA primer with DNA, Ligase seals all of the ends together.
What is PCR?
Makes many copies of genes present in a sample
What factors impact the effectiveness of microbial control
population size, composition, concentration or intensity, contact time, temperature, and local enviorment
What are the 5 methods of drug action
inhibit cell wall synthesis
inhibit nucleic acid structure and function
inhibit protein synthesis
interfere with cytoplasmic membrane
inhibit folic acid syntehsis