MIC 102 Exam 1 Questions with Correct Answers

MIC 102 Exam 1 Questions with Correct Answers Which type of cell is most susceptible to osmotic lysis in an environment with a very low concentration of solutes (hypotonic)? - Answer-Mycoplasma Which of the following cellular structures self-assemble (purified monomers can assemble into the structure without added factors or the input of energy)? - AnswerFlagellar filament Phospholipid bilayer S layer mycoplasma - Answer-only prokaryotic group listed that do not have a cell wall to resist high osmotic pressure caused by water moving into the solute-rich cell While Mycoplasma are highly successful inside the relatively isotonic environment inside a host's body, they do not fare well in hypotonic environments or culture media. how does phospholipid bilayer assemble? - Answer-phospholipid nonpolar tails are attracted to each other to escape the hydrophilic environment surrounding them how does flagellar filament assemble? - Answer-Flagellin aggregates spontaneously at the tip of the flagellar filament during flagellar assembly how does the S layer assemble? - Answer-The S-layer is a lattice of a single protein that will self-assemble into highly-ordered arrays how do pili assemble? - Answer-built of monomers of the protein pilin that are added to the base of the pilus filament What distinguishes an organelle (such as a mitochrondrion or chloroplast) from a carboxysome or enterosome? - Answer-Organelles may contain DNA carboxysomes - Answer-protein-enclosed compartments where bacteria concentrate the enzymes and substrates forcarbon fixation enterosomes - Answer-protein-enclosed compartments where bacteria concentrate the enzymes and substrates for propanediol and ethanolamine metabolism DNA may be observed in which forms inside Bacterial cells? - Answer-Circular chromosomes what is bacterial DNA like? - Answer-single circular chromosome bound by DNAcondensing proteins Positively-charged cations in the cytoplasm reduce the electrostatic repulsion of negatively-charged DNA and allow its condensation into higher-ordered loops and supercoiled structures Bacteria may also have circular plasmids, which encode functions not essential for survival (note: a cell may be "cured" of a plasmid but never of a chromosome) T/F: Only prokaryotes can transcribe and translate a gene at the same time. - Answer-true