Microbiology

Question 1

What type of bacteria have an outer membrane?

Answer 1

Gram-Negative

Question 2

What is small enough to pass through a sieve filter?

Answer 2

viruses (bacteria are too large)

Question 3

What is the structure of a gram positive exterior?

Answer 3

cell membrane-cell wall

Question 4

What is a spherical morphology?

Answer 4

coccus

Question 5

What is the first stain used in gram staining?

Answer 5

crystal violet

Question 6

What is the decolorizing agent in gram staining?

Answer 6

ethanol

Question 7

What is the counter stain?

Answer 7

safranin

Question 8

What color are Gram +?

Answer 8

violet

Question 9

What color are Gram -?

Answer 9

pink

Question 10

What is the end result of fermentation?

Answer 10

lactic acid and a drop in pH

Question 11

What is the product of amino acid catabolism?

Answer 11

an alkaline environment

Question 12

What do bacterial cell membranes lack that eukaryotic membranes have?

Answer 12

cholesterol

Question 13

What drug targets bacterial RNA polymerase?

Answer 13

Rifampin

Question 14

What molecule is involved in bacterial DNA replication?

Answer 14

DNA gyrase

Question 15

What metabolic process is unique to bacteria?

Answer 15

folate or folic acid synthesis

Question 16

What type of bacteria have a thick peptidoglycan wall?

Answer 16

Gram positive

Question 17

What phospholipid is most common in bacterial membranes?

Answer 17

Phosphotidylethanolamine

Question 18

What are the three functions of a membrane?

Answer 18

1. Permeability barrier
2. Protein anchor
3. Energy Conservation

Question 19

What are the types of active transport?

Answer 19

uniport, symport, antiport

Question 20

What are the main components of the peptidoglycan wall?

Answer 20

1. NAM
2. NAG
3. Pentapeptide (for crosslinking)

Question 21

What is unique about bacterial amino acids?

Answer 21

often in the D conformation

Question 22

What is the purpose of the peptidoglycan wall?

Answer 22

mesh like structure that keeps the cell from bursting

Question 23

What is DAP?

Answer 23

diaminopimelic acid

lysine with an extra amino group

Question 24

What type of linkage is between NAG and NAM?

Answer 24

beta 1,4 (transglycosylation)

Question 25

Where is the pentapeptide chain attached?

Answer 25

NAM

Question 26

What is the unique amino acid in the Gram + pentapeptide chain?

Answer 26

L-Lys

Question 27

What is the unique amino acid in the Gram - pentapeptide chain?

Answer 27

DAP

Question 28

How are two chains cross linked in Gram -?

Answer 28

Transpeptidation; DAP to D-Ala

Question 29

Where does the energy for cross linking come from?

Answer 29

breaking the D-Ala and D-Ala bond

Question 30

What is involved in transpeptidation of Gram + bacteria?

Answer 30

L-Lys + Gly(5) + D-Ala

Question 31

What is Gly(5)?

Answer 31

pentaglycine bridge that increases the size of peptidoglycan wall in Gram + bacteria

Question 32

What molecules hydrolyze beta 1,4 linkages?

Answer 32

autolysins

Question 33

What protein flips subunits of peptidoglycan out from the cytosol for polymerization?

Answer 33

bactoprenol

Question 34

What drug blocks bactoprenol and leads to increased levels of subunits of peptidoglycan wall in the cytoplasm?

Answer 34

bacitracin

Question 35

What is the role of penicillins?

Answer 35

block transpeptidation

Question 36

What are two of the features of the GP peptidoglycan wall?

Answer 36

teichoic and lipoteichoic acid

Question 37

What TLR binds teichoic and lipoteichoic acid?

Answer 37

TLR 2

Question 38

What part of the GN wall leads to sepsis?

Answer 38

lipid A or endotoxin

Question 39

What is the composition of LPS?

Answer 39

Lipid A + core + O-antigen

Question 40

Where is lipid A?

Answer 40

it is the outer leaflet of the outer membrane in GN bacteria

Question 41

What antigen is associated with flagella?

Answer 41

H-antigen

Question 42

What are the three parts of a flagellum?

Answer 42

Basal body + Hook + filament

Question 43

What is the type 3 secretion system?

Answer 43

translocate virulence effector proteins made in bacteria into host cytoplasm

Question 44

What is the role of pili (fimbriae)?

Answer 44

adhesion, twitching motility, conjugation

Question 45

What is a network of polysaccharide or protein that is secreted outside of the bacteria?

Answer 45

glycocalyx

Question 46

How are slime layers attached?

Answer 46

loosely

Question 47

What is the role of glycocalyx?

Answer 47

prevent penetration of antimicrobial compounds and prevent phagocytosis by host immune cells

Question 48

What bacteria has a good glycocalyx?

Answer 48

Streptococcus pneumoniae

Question 49

What is a biofilm?

Answer 49

secretion of polysaccharides that allow bacterial aggregation

Question 50

What is the role of biofilms?

Answer 50

adhesion, communal growth, resistance to disinfectants and antimicrobials

Question 51

What phase of bacterial growth contains replication and cell division?

Answer 51

Log phase or exponential phase

Question 52

How do bacteria divide?

Answer 52

binary fission

Question 53

What are some of the properties of stationary phase cell?

Answer 53

resistant to acidic pH, heat shock, and oxidative stress

Question 54

What is anaerobic metabolism?

Answer 54

fermentation

Question 55

What are some of the products of anaerobic metabolism?

Answer 55

lactate, acetate, ethanol, H2, pyruvate

Question 56

What is the purpose of the ETS?

Answer 56

energy coupling