Growth Metabolism

Question 1

What is a nucleoid?

Answer 1

supercoiled, single chromosome

Question 2

What is a plasmid?

Answer 2

genetic info that replicated independently of nucleoid

Question 3

What is the only organelles in bacteria?

Answer 3

70s ribosomes

Question 4

What is the cell wall of bacteria made of?

Answer 4

peptidoglycan

Question 5

What is an endospore?

Answer 5

allows some bacteria to survive harsh conditions

Question 6

What is a capsule?

Answer 6

anti-phagocytic

Question 7

What is a pilli?

Answer 7

• attachment
• delivery of toxins
• exchange of genetic info

Question 8

What are the cell shapes of bacteria?

Answer 8

• round -> coccus
• bacillus -> rod shaped
• spirochete -> cork-screw

Question 9

What is lipopolysaccharide (LPS)?

Answer 9

• made of: repeating O Ag, core polysaccharide, lipid A

Question 10

What has endotoxic effects that actovates inflammatory mediators?

Answer 10

lipid A -> can lead to septic shock

Question 11

What are the 4 phases of bacterial growth?

Answer 11

1. lag -> bacteria acclimate to new environment
2. log -> exponential growth of bacteria
3. stationary -> no significant net change in population
4. death -> when population declines

Question 12

What are the steps in gram staining?

Answer 12

1. crystal violet -> stains everything purple
2. gram iodine -> stabilizes purple color
3. decolorizer -> alcohol or acetone; becomes colorless
4. safranin red -> stains anything not stained red

Question 13

What are the 4 types of bacteria?

Answer 13

• gram-positive rods & cocci
• gram negative rods & cocci

Question 14

What are the characteristics of gram +?

Answer 14

• no outer membrane
• thick peptidoglycan
• no LPS

Question 15

What are the characteristics of gram -?

Answer 15

• has outer membrane
• thin peptidoglycan
• outer membrane has LPS & porins
• large periplasmic space

Question 16

What makes up a peptidoglycan?

Answer 16

• N-acetylmuramic acid & N-acetylglucosamine
• cross-linking holds sugars together via peptides from N-acetylmuramic acid

Question 17

What causes 80% of UTIs?

Answer 17

europathogenic e. coli

Question 18

What type of toxicity does bacteria show?

Answer 18

selective toxicity

Question 19

What is bacteriostatic?

Answer 19

prevents growth but DOES NOT kill them

Question 20

What is bacteriocidal?

Answer 20

kills bacteria

Question 21

What is an example of a narrow spectrum of bacteria?

Answer 21

benzyl penicillin

Question 22

What is an example of a broad spectrum of bacteria?

Answer 22

tertacycline

Question 23

What is MIC?

Answer 23

minimum conc. of drug to stop growth of bacteria

Question 24

What are peptidoglycan synthesis inhibitors?

Answer 24

• ex: penicillins & cephalosporins
• beta-lactam
• bind to penicillin binding protein
• leads to cell lysis (bacteriocidal)

Question 25

What are nucleic acid synthesis inhibitors?

Answer 25

• bacteriocidal
• prevent DNA replication/transcription
• bactericidal
• ex: quinolones -> inhibit DNA gyrase & rifampin -> inhibit DNA-dependent RNA poly

Question 26

What is the role of tetracyclines as a protein synthesis inhibitor?

Answer 26

• bacteriostatic
• prevent aminoacyl-tRNA from binding to 30S subunit
• fights against obligate intracellular bacteria

Question 27

What is the role of amidoglycosides as a protein synthesis inhibitor?

Answer 27

• bactericidal
• causes misreading of mRNA
• binds to 30S subunit & prevents translocation

Question 28

What is the role of macroslides as a protein synthesis inhibitor?

Answer 28

• bacteriostatic
• binds to 50S subunit
• used against legionellae & mycoplasma
• resistance through modifying rRNA

Question 29

What inhibits steps in the folic acid biosynthesis pathway?

Answer 29

trimethoprim & sulfanilamide

Question 30

What are the characteristics of folic acid synthesis inhibitors?

Answer 30

• bacteriostatic
• resistance through decreased permeability (T) or target modification (S)
• ex: trimethoprim & sulfanilamides