Lecture 1a Bacterial Cell Structure

Question 1

Monotrichous

Answer 1

Bacterial flagella

-Single flagella
Ex. Vibrio Cholerae

Question 2

Lophotrichous

Answer 2

Bacterial Flagella

-Multiple Flagella at one end
Ex. Bartonella baciliformis

Question 3

Amphitrichous

Answer 3

Bacterial Flagella

-Multiple Flagella at both ends
Ex. Spirillium Serpens

Question 4

Peritrichous

Answer 4

Bacterial Flagella

• Multiple flagella around entire surface
  Ex. Escherichia coli

Question 5

What type of flagella do Spirochetes have?

Answer 5

Endoflagella

Question 6

Pili (Fimbriae)

Answer 6

Bacterial adhesion

Protein cylinders that allow initial interactions with other cells

• Help overcome electrostatic repulsion
• Pili bind to specific receptors

Question 7

Afimbrial Adhesion

Answer 7

Surface proteins not organized into a defined structure.

-Important in tight binding to host cells.

Question 8

Gram Positive

Answer 8

Stains Purple

• Thick peptidoglycan layer
• No outer membrane

Question 9

Gram Negative

Answer 9

Stains Red/Pink

• Thin Peptidoglycan layer
• Outer membrane

Question 10

Peptidoglycan composition

Answer 10

Alternating units of:

• N-Acetyl glutamic acid (NAG)
• N-Acetyl muramic acids (NAM)

Question 11

Lipopolysaccharide

Answer 11

Only in Gram Negative

• Makes outer membrane impermeable
• O Antigen
• Core Region
• Lipid A

Question 12

O Antigen

Answer 12

Component of Lipopolysaccharide

• External
• Highly variable
• Connects to core

Question 13

Core Region

Answer 13

Component of Lipopolysaccharide

• Inner (unique heptose sugars & KDO)
• Outer Core (hexose sugars)

Question 14

Lipid A

Answer 14

Component of Lipopolysaccaride

-Membrane anchoring

Question 15

LPS toxic & immunostimulatory activities are due to…

Answer 15

The chemical makeup of lipid A

-Endotoxic effects only happen when cell breaks open.

Question 16

Fever

Answer 16

Physiological Response to LPS

-LPS stimulates production & release of pyrogenic cytokines

Question 17

Neutropenia

Answer 17

Physiological response to LPS

-Transient, neutrophils get sequestered in the organs lowering neutrophil count

Question 18

Disseminated intravascular coagulation (DIC)

Answer 18

Physiological response to LPS

• Clotting
• Platelets stick to & block small blood vessels

Question 19

Hypotension

Answer 19

Physiological response to LPS
Low blood Pressure

• Vascular leakage
• C3a & C5a attract PMNs that stick to endothelial cells
• Lysosomal enzyme release occurs, damaging endothelium
• Vascular collapse (septic shock), multi organ system failure