Cell wall gram -ive

Question 1

What is the cell wall composed of

Answer 1

thin layer of peptidoglycan covered by an outer membrane

Question 2

Describe the peptidoglycan of gram -ive

Answer 2

penta peptide are composed of same aa in gram +ive except L-lysine is replaced with di-amino-pimelic acid (DAP)

Question 3

Describe di-amino-pimelic acid (DAP)

Answer 3

like lysine it has an amino group as part of its R group

Question 4

What is the diff between gram -ive and +ive linkage

Answer 4

gram i-ve: linkage btwn peptide is direct, there is no inter bridge. compared to gram +ive, there are fewer layers and cross bridges formed

Question 5

Descibe the OM of gram -ive

Answer 5

lipid bilayer w/integral proteins

Question 6

What is the OM of composed of

Answer 6

inner leaflet is composed of phospholipid, outer leaflet composed of lipo-poly-sachharide (LPS)

Question 7

What is only found in gram -ive bacteria that is found in OM

Answer 7

LPS lipo-poly-saccharide

Question 8

Describe lipo-poly-saccharide (LPS) structure

Answer 8

derived from 3 components, lipid A, core polysaccharide and O antigen

Question 9

Describe the lipid A

Answer 9

2 glucose amines form a disaccharide. each sugar has phosphate attached. 6 fatty acid attach to disaccharide

Question 10

What is another name for lipid A

Answer 10

endotoxin

Question 11

If released into blood what can lipid A (endotoxin) cause

Answer 11

fever, shock, and death

Question 12

Describe the core polysaccharide

Answer 12

composed of several diff sugars, some sugars are phosphorylated

Question 13

Describe the O antigen

Answer 13

composed of sugars in repeating sequence forming a polysaccharide, can vary btwn strains of bacteria

Question 14

give an example of variant in species with O antigen

Answer 14

E. coli O-157:H7, O refers to O antigen

Question 15

How is the surface charge of LPS produced

Answer 15

core polysaccharide region’s phosphates