September 14 Pop Quiz

Chapter 5:
*Give an example of a beta-lactam antibiotic. How do beta-lactam antibiotics kill bacteria?
An example would be penicillin- peptidoglycan molecules are linked together and the beta-lactams stop the enzyme that links the peptidoglycans
*What is an "autolysin?" Why do bacteria make autolysins?
They are bacterial cytoplasmic membrane proteins that break down peptidoglycan
*Why aren't gram-negative bacteria killed by vancomycin?
Because gram-negative has a thick outer membrane and vancomycin is not able to get through
*How have bacteria become resistant to beta-lactam antibiotics?
Because of beta-lactamase which is an enzyme that destroys beta-lactams
*Are any gram-positive bacteria resistant to vancomycin? What might account for this resistance?
yes

Chapter 6:
*Name 2 drugs that block bacterial ribosomes. Why does stopping translation kill the cell, even if it's not dividing?
Streptomycin and Zithromax. Proteins are essential for cell to function so if you can't make them, you die
*Why doesn't Zithromax hurt human cells?
Our ribosomes are different enough from zithromax that they aren't harmed
*Why isn't tetracycline prescribed for pregnant women or young children in first-world countries?
It goes into your bones and it also turns teeth permanently yellow
*List two ways that bacteria can become resistant to antibiotics that stop protein synthesis.
1. The efflux pump is a structure that some bacteria make and it pumps antibiotics out
*At high drug concentrations the efflux pump won't allow bacteria to resist drug

Chapter 7:
*How does rifampin work? What infection is it used to treat? Would rifampin kill archaea?
It inhibits RNA polymerase. It treats TB and bacterial meningitis. No it would not kill archaea.
*Why does isoniazid kill tuberculosis bacteria but not gram-positive or gram-negative bacteria?
TB is an Acid-fast bacteria and therefore has mycolic acid and isoniazid which would blow up other bacteria.
TB does not stain gm (+) or gm (-)
*What is the target of ciprofloxacin? Why does ciprofloxacin kill bacteria, even when they are not dividing?
It binds to DNA gyrase. They can't unwind their DNA. Ciprofloxacin attacks bacterial DNA gyrase

Chapter 10:
*What is the difference between an antiseptic and an antibiotic?
Antiseptic is applied topically and an antibiotic is taken orally
*What is the difference between an antiseptic and a disinfectant?
*What cellular feature do halides destroy? Give an example of a halide that is used as an antiseptic, and an example of a halide that is used as a disinfectant.
*What cellular feature do alcohols destroy?
*Give an example of an alkylating agent. Why do alkylating agents kill cells?
*Why do heavy metals kill cells? Give an example of a heavy metal used as an antiseptic.
*Can bacteria ever become resistant to disinfectants?
*Why is resistance to antibiotics "easier" to evolve than resistance to disinfectants is?

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