Biological Attributes of Bacteria

Question 1

What component of the bacterial envelope functions in adhesion to host cells?

Answer 1

Pili, proteins, teichoic acid

Question 2

What component of the bacterial envelope functions in motility?

Answer 2

Flagella

Question 3

What components of the bacterial envelope function in metabolite uptake?

Answer 3

Membranes and periplasmic transport proteins, porins, permeases

Question 4

Teichoic acid and lipoteichoic acid are only present in what type of bacterial cell?

Answer 4

Gram +

Question 5

What is found in the periplasmic space of Gram- cell envelopes?

Answer 5

Peptidoglycan, hydrolytic enzymes, sugar transport systems, components of the chemotaxis system

Question 6

Describe the parts of LPS.

Answer 6

• O-antigen: highly variable polysaccharides, induces immune response
• Core: heptoses, ketodeoxyoctonic acid
• Lipid A: glucosamine dissacharide, beta hydroxy fatty acids: IL-1 secretion, Schwarzman reaction (clotting mechanism), disseminated intravascular reaction, induction of TNF

Question 7

How does transglycosylase act during peptidoglycan synthesis?

Answer 7

Catalyzes formation of beta-1,4 glycosidic bonds (joins new NAG-NAM disaccharide units)

Question 8

How does transpeptidase act during peptidoglycan synthesis?

Answer 8

Forms peptide cross-bridges between adjacent glycan strands (specific linkage between epsilon-amino group of lysine at position 3 of one peptide and the D-alanine at position 4 of another peptide)

Question 9

Describe the capsule/glycocalyx.

Answer 9

• Outer polysaccharide layer (either a thick outer viscous polysaccharide gel, capsule, or a more amorphous slime layer)
• Mostly polysaccharide in nature
• Important virulence factor
• Antigenic