MIC 401 EXAM 2 QUESTIONS ANSWERED CORRECTLY LATEST UPDATE 2026

MIC 401 EXAM 2 QUESTIONS ANSWERED CORRECTLY LATEST UPDATE 2026 Cocci - Answers Spherical bacteria Strep - Answers A chain of cocci Staph - Answers Cluster of cocci Bacilli - Answers Rod shaped bacteria Palisades - Answers A cluster of bacilli arranged together Vibrio - Answers Bent bacillus, comma shaped Coccobacillus - Answers Short, round rod Spirochetes - Answers Corkscrew shaped bacteria Peptidoglycan - Answers 2 repeating disaccharides, NAG and NAM, crosslinked by tetrapeptides Gram negative - Answers Thin layer of peptidoglycan between 2 bilayers Cell wall ( gram negative ) - Answers outer membrane and peptidoglycan Periplasmic space - Answers Space between the outer membrane and the peptidoglycan Mycolic acid - Answers Outer waxy lipid layer, very difficult for antibiotics to penetrate Chemotaxis - Answers Bacteria move in random directions towards chemical stimulus Run and tumble - Answers Move quickly in random direction, then reorient towards stimulus Pilus - Answers Hair like appendage made of pilin, useful for adhesion Conjugative pili - Answers DNA transfer between bacteria Type IV Pili - Answers Movement along solid surface, impt for vibrio cholerae Glycoclalyx - Answers Viscous, gummy layer of polysaccharides Slime Glycocalyx - Answers Loose-coating, doesn't exclude small particles Capsule - Answers Tightly attached, and excludes small particles. Useful for immune evasion. R-plasmid - Answers Resistance plasmid, contains genes responsible for antibiotic resistance F-plasmid - Answers Fertility plasmid, facilitates gene exchange. Magnetosomes - Answers Contain iron, align with magnetic fields Endospores - Answers Metabolically inactive structures made in time of extreme stress - lets bacteria enter dormant state, made by Gram + bacteria Sporulation - Answers 1. DNA replicated 2. Cytoplasmic membrane pinching 3. Host DNA disintegrates as membrane engulfs forespore in second layer 4. Cortex deposited, spore coat forms 5. Endospore matures, original cell lyses Macronutrients - Answers N2, H2, CO2, C, Ca2+, PO4, Fe, S Micronutrients - Answers Mn2+, Zn2+ Prototrophs - Answers Derive all requirements from artificial media Fastidious - Answers Need special vitamins/amino acids in their media Phases of bacterial growth - Answers Lag, log, stationary, death Cas gene - Answers encodes a nuclease that cuts DNA at specific repeats sgRNA - Answers single guide RNA which guides the nuclease to cut at specific target sites PAM site - Answers The site where Cas9 and sgRNA cleave DNA Methods of introducing Cas9 into cells - Answers Microinjection ( single cell delivery ) Engineered virus Liposome-mediated delivery Electroporation CRISPR mutagenesis - Answers Cas9 cleaves DNA, leads to NHEJ, which deletes the gene and inactivates the protein Introduce foreign DNA - cell anneals in place of damage Lysogenic conversion - Answers A bacterium acquires a new trait from its temperate phage Plaque assay - Answers Serial dilutions of bacterial lysate to molten agar, allows you to harvest phage Lytic cycle - Answers Adsorption, Penetration, Inject DNA, early proteins assembled, host chromosome disassembled, viral DNA and proteins assembled, phage lyses Latent period - Answers Adsorption to lysed cells Eclipse period - Answers Adsorption to assembled phage cos sites - Answers sites at which lambda phage DNA circularizes, G-C rich, strong H-bonds Lytic promoters - Answers Pl and Pr Lysogenic promoters - Answers Prm, Pre Pre activation - Answers C1 ( repressor ) upregulates, shuts down PL and PRE Pr activation - Answers Cro ( antirepressor ) upregulates, represses production of C1, allows Pl and Pr to activate Theta replication - Answers TER cleave COS site, leaving ssDNA to recircularize Superinfection immunity - Answers C1 from last attack binds to new secondary phage DNA and represses lytic cycle, and no available attB sites for lysogenic cycle Integrase function - Answers Recombines attP and attB sites to make attBP, inserting phage DNA into host DNA RecA - Answers protease that cleaves C1 in bacteria Xis recombinase - Answers Induced by stress and low C1, which cleaves attBP sites and releases phage DNA, entering the lytic cycle Broad spectrum antibiotics - Answers Effective against Gram negative and Gram positive bacteria Narrow spectrum antibiotics - Answers Only Gram neg or Gram positive bacteria, less disruptive to normal microbiota Limited antibiotic - Answers Specific against one organism Empiric therapy - Answers Use broad spectrum while waiting for culture and slowly narrow down - based on doctor's educated guess Bacteriostatic drugs - Answers Inhibit protein synthesis and metabolic pathway, reliant on immune response Bactericidal drugs - Answers Target cell wall or nucleic acid, non-immune reliant Prophylaxis - Answers Antibiotics preventing infection Pathogen-directed - Answers Organism known but susceptibility to drugs unknown Susceptibility-guided - Answers Organism and drug susceptibility known Selective toxcitiy - Answers Toxic only to pathogen, not the host Oral rout - Answers Most preferred, but needs to be stable in stomach Beta lactam drugs - Answers Target peptidoglycan by preventing crosslinking via transpeptidase Beta lactamase - Answers Cleave Beta lactam ring Antiviral drugs - Answers Target replication cycle or stimulate interferons Anti-fungal drugs - Answers Target cell-wall synthesis or nucleic acids Antiparasitic - Answers Incredibly difficult to create due to complex life cycles - but try to target intracellular compounds AST - Answers Antibiotic susceptibility testing - test all patient discharge and identify resistances Kirby-Bauer = - Answers Disk diffusion - see if zone of inhibition appears, and measure diameter to see resistances E test - Answers Strips of drug gradient placed on agar - find inhibition zone Minimal Inhibitory Concentration ( MIC ) - Answers Minimal amount of drug that is required to stop growth MIC test - Answers Use serial dilution and test for concentration that stops visible growth via turbidity or colorimetric means. MBC - Answers Dilution with 99% reduction compared to the inoculum Intrinsic resistance - Answers Inherent to physiology - eg) bacteria with no peptidoglycan can't be targeted by beta-lactams, or mycolic acid can't be targeted well with drugs Acquired resistance - Answers Genetic mutation taken through resistance genes - usually alter drug target, or inactivate drug, or reduce concentration Staphylococcus - Answers Gram positive, non-spore, nonmotile, no capsule Catalase - Answers Divides H2O into water and oxygen, present in staphylococcus Coagulase - Answers Present in aureus and not other staph, enables host fibrinogen to fibrin conversion S. epidermidis - Answers lives on skin in normal microbiota: leads to endocarditis, UTI S. saprophyticus - Answers infrequently lives on skin, intestine, vagina; UTI Clumping factor - Answers Coagulase bound to cell wall Teichoic acid - Answers Adhesion, immune system doesn't generate memory