Introduction to Microbes

Question 1

What is bacteria cell wall made of?

Answer 1

peptidoglycan.

lipopolysaccharide.

Question 2

What is peptidoglycan?

Answer 2

a complex carbohydrate that forms a strong mesh surrounding the cell.

Question 3

What is lipopolysaccharide?

Answer 3

teichoic acid.

Question 4

Features of gram positive bacteria?

Answer 4

1. thicker peptidoglycan layer.

2. appears purple.

Question 5

Features of gram negative bacteria?

Answer 5

1. thinner peptidoglycan layer
2. appears pink
3. has second lipid membrane that is exposed to the outside environment.

Question 6

Features for gram staining?

Answer 6

stain with crystal violet, treat with iodine, wash with alcohol, stain red.

Question 7

features of flagella?

Answer 7

motility - ability to move spontaneously and actively.

rotate like a propeller.

Question 8

What is flagella made of?

Answer 8

flagellin.

Question 9

features of pili/fimbriae?

Answer 9

project from cell’s surface. aid in adherence (ends are like hooks).

Question 10

what do pili/fimbriae help form?

Answer 10

biofilm.

Question 11

What is a capsule also called?

Answer 11

• glycocalyx - sugar cap.
• hydrated polysaccharide layer that surrounds the cell.
• provide survival advanatges.

Question 12

What survival advantages does a capsule provide?

Answer 12

1. protect bacteria from drying.
2. resist phagocytes.
3. molecular mimicry - look so similar to the polysaccharides in the body
4. adherence.