MCB 2610 Lab final (Questions & Answers) Rated 100%

Differential media - allow certain bacteria to be differentiated from others by change of color, zone of clearing, or other Bacteria can prevent phage attachment and escape infection by acquiring mutations on genes which alter their _________. - cell surface receptors A _______ agent does not kill a microorganism, but rather just inhibits its growth. - bacteriostatic A clear area surrounded by growth of host cells is called a _______. - plaque A color change to yellow on the mannitol salt agar plate indicates what possible organism? - S. aureus Absorbance - the change in optical density Aerobes - require oxygen After a Gram negative test, bacteria are separated by: - oxidase test After a Gram positive test, bacteria are separated by: - cell morphology Alpha hemolysis - green cloudy zone around growth, normal Amylase - catalyzes starch hydrolysisAn antibiotic that is effective against a wide variety of pathogenic microorganisms is called a _________ antibiotic. - broad spectrum Anaerobes - don't need oxygen Antibiosis - inhibitory effect of antibiotics Antibiotic - antimicrobial substance produced by a microorganism Antimicrobial - inhibits growth or kills microorganism Antiseptics - used on living tissues Bacteria grow best in _______ ______. - moist areas Bactericidal - kills organisms Bacteriophage or phage - virus that infects bacteria Beta hemolysis - clear zone around growth, pathogenic Brownian motion - random collisions with water molecules Caseinase - hydrolyze casein into peptides Catalase - protects cells from hydrogen peroxide Coliforms are a subgroup of enteric bacteria classified by their ability to ferment which sugar? - lactoseColiforms are: - an indicator organism Gram negative found in GI tract ferment glucose resistant to detergents Complex media - exact chemical composition of media is unknown Confirmed test - postive presumptive test tubes streaked onto EMB agar to verify presence of coliforms direct stain - stains the organism itself Disinfectants - used on inanimate objects to decrease number of microbes Disinfectants and antiseptics are both: - concentration dependent Durham tube - inverted vial to study fermentation During the lytic infection, what does the phage particle inject into the host cell after attachment? - its genome End products of fermentation are always _____ and sometimes _____. - acids, gas EnterioPluri-Test is used to test on - Enterobacteria Facultative anaerobes - can grow with or without oxygen