Exam 2 Microbiology Prep

Front 1

What are the targets for antimicrobial drugs?

Back 1

Inhibits cell wall synthesis

Inhibits RNA and DNA structure and function

Inhibits protein synthesis

Interferes with cell membrane structure and function

Inhibit folic acid synthesis (metabolism)

Front 2

How do beta lactams work?

Back 2

Inhibit and enzyme called transpeptidase. This enzyme is a penicillin binding protein that keeps the penicillin chains bound together as the cell wall expands.

Beta lactams bind to the active site of transpeptidase (the part the protein that’s doing the job). This binding is irreversible.

This inhibits cell wall synthesis and causes breaks that will lead to the cells contents leaking out through the cracks in the cell wall.

Front 3

Penicillin

Back 3

Beta lactams

Broad spectrum

Inhibits cell wall synthesis

Front 4

Carbapenems

Back 4

Beta lactam

Inhibits cell wall synthesis

Front 5

Streptomycin

Back 5

Antibiotic

Binds to 30s rRNA, causing misreading of mRNA and ultimately, bad proteins

Front 6

Erythromycin

Back 6

Inhibit translocation of subunit during translation. Target 50s.

Front 7

Polymyxin B

Back 7

Narrow spectrum antibiotic

Only works on gram negative because it can’t get through the thick layers of peptidoglycan in gram +.

Creates leaky cell membranes so important parts leak out of cell and messes up osmotic pressure.

Front 8

Rifampin

Back 8

Narrow spectrum antibiotic

Only works on gram +.

Can’t cross outer membrane of gram -.

Inactivates RNA polymerase.

Front 9

Ciprofloxacin

Back 9

Broad spectrum antibiotic

Blocks DNA replication

Front 10

Ciprofloxacin

Back 10

Broad spectrum antibiotic

Blocks DNA replication

Front 11

Tetracycline

Back 11

Antibiotic

Blocks attachment of tRNA and stops protein synthesis

Front 12

Ciprofloxacin

Back 12

Broad spectrum antibiotic

Blocks DNA replication

Front 13

Tetracycline

Back 13

Antibiotic

Blocks attachment of tRNA and stops protein synthesis

Front 14

Vancomycin

Back 14

Narrow spectrum antibiotic

Too large to diffuse through outer membrane of gram -.

Binds to peptidoglycan and prevents cross bridges, inhibiting cell wall synthesis.

Front 15

Acyclovir

Back 15

Terminates DNA replication in herpesvirus

Front 16

Acyclovir

Back 16

Terminates DNA replication in herpesvirus

Front 17

Oseltamavir

Back 17

Blocks neuraminidase enzyme on influence, prevents the release of viral particles

Front 18

Acyclovir

Back 18

Terminates DNA replication in herpesvirus

Front 19

Oseltamavir

Back 19

Blocks neuraminidase enzyme on influence, prevents the release of viral particles

Front 20

AZT

Back 20

Thymidine analogue

Used by HIV’s reverse transcriptase instead of thymidine during DNA synthesis, halts DNA synthesis

Front 21

Ribivarin

Back 21

Prevents nucleic acid synthesis for RNA viruses like HCV or RSV

Front 22

What are mechanisms of antimicrobial resistance?

Back 22

Efflux pump: when things get into the bacterium, it pumps it right back out of it

Blocked penetration: the bacteria has found a way to prevent antibiotics from even getting in

Inactivation of enzymes: bacteria will make enzymes that inactivate antibiotics (beta lactamase breaks the beta lactam ring)

Target modification: the bacteria changed where the antibiotic used to bind. The process happens gradually as mutations begin to accumulate.

Front 23

What are the commonly used physical methods to control microbes?

Back 23

Moist heat

Dry heat

UV radiation

Osmotic pressure

Filtering

Front 24

How is moist heat used to control microbes?

Back 24

Pasteurization: used to remove pathogenic bacteria without altering certain chemical properties of liquid. Heating liquid and cooling it quickly. Does not sterilize.

Boiling: heating liquid up to boiling. Does not sterilize.

Autoclaving: combination of boiling temperatures and high pressures. DOES sterilize.

Front 25

How is moist heat used to control microbes?

Back 25

Pasteurization: used to remove pathogenic bacteria without altering certain chemical properties of liquid. Heating liquid and cooling it quickly. Does not sterilize.

Boiling: heating liquid up to boiling. Does not sterilize.

Autoclaving: combination of boiling temperatures and high pressures. DOES sterilize.

Front 26

How does dry heat control microbes?

Back 26

Flaming: exposing objects directly to a flame reduces microbes to ash. DOES sterilize.

Baking: hot air oven. Requires 2-4 hours. DOES sterilize.

Front 27

How does UV radiation control microbes?

Back 27

It exposes items to UV rays which damages DNA.

Only works on surfaces directly exposed to UV radiation.

does not sterilize.

Front 28

How does UV radiation control microbes?

Back 28

It exposes items to UV rays which damages DNA.

Only works on surfaces directly exposed to UV radiation.

does not sterilize.

Front 29

How does osmotic pressure control microbes?

Back 29

Adding high amounts of salt or sugar to a liquid.

Does not sterilize, but does inhibit growth.

Front 30

How does filtering control microbes?

Back 30

Liquid is strained through a filter with holes too small to allow microbes to pass.

Effective in removing bacteria (including endospores). Extremely small pore sizes will work on viruses.

DOES sterilize.

Used on liquids that can’t be heated.

Front 31

What are some chemical methods to control microbes?

Back 31

Peroxygens

Hexachlorophene

Iodine

Silver nitrate

Isopropanol

Chlorine

Hint 31

PHISIC

Front 32

How do peroxygens control microbes?

Back 32

They produce free radicals that damage cells.

Front 33

How do peroxygens control microbes?

Back 33

They produce free radicals that damage cells.

Front 34

How does hexachlorophene control microbes?

Back 34

It targets membranes/respiration.

Most effective on gram +.

Front 35

How does iodine control microbes?

Back 35

It’s a halogen.

It interferes with bonding in proteins. Can kill all microbes and endospores slowly.

Antiseptic.

Front 36

How does silver nitrate control microbes?

Back 36

It’s a heavy metal. Inactivates enzyme activity.

Can kill most bacteria and viruses but not endospores.

Front 37

How does chlorine control microbes?

Back 37

Halogen.

It denatures cellular enzymes.

Kills all microbes and endospores slowly.

Front 38

How does chlorine control microbes?

Back 38

Halogen.

It denatures cellular enzymes.

Kills all microbes and endospores slowly.

Front 39

How does isopropanol control microbes?

Back 39

Alcohol.

Dissolved membranes and can Denature proteins with extended exposure.

Works on most bacteria and enveloped viruses.

Antiseptic.