Lab 5

Question 1

Glycocalyx

Answer 1

a mix of polysaccharides and polypeptides.

Loosely bound = slime layer
Tightly bound = capsule

Question 3

Virulence factor

Answer 3

increases the likelihood of an infectious disease

*makes bacterium a more successful pathogen

Question 4

Phagocytosis

Answer 4

the ingestion of bacteria or other material

Question 5

Opsonization

Answer 5

an immune process which uses opsonins to tag foreign pathogens for elimination by phagocytes

Question 6

Biofilms

Answer 6

a collective of one or more types of microorganisms that can grow on many different surfaces.

*increased virulence and antibiotic resistance

Question 7

Endospores

Answer 7

structures that form inside of some bacteria

the dormant, tough, and non-reproductive structure produced by certain bacteria

Question 8

Endospore

Germination cycle -

Sporulation cycle -

Answer 8

The germination cycle - is the change of an endospore from its resting stage to an actively growing vegetative cell. This takes place when the external environment is favorable for growth by the provision of essential nutrients and water.

Sporulation cycle - the formation of spores from vegetative cells during unfavorable environmental conditions

Question 9

Flagella

Answer 9

bacteria appendages that allow bacteria to move

Composed of protein, flagellin

Question 10

Flagella arrangements

1 at 1 pole

several at 1 pole

1 at each pole

many around the cell

Answer 10

Monotrichous

Lophotrichous

Amphitrichous

Peritrichous

Question 11

Mordant

Answer 11

combines dye or stain and fixes it to a material

Question 12

Turbidity

Answer 12

the measure of relative clarity of a liquid

Question 13

Absorbance

Answer 13

a measure of the capacity of a substance to absorb light of a specified wavelength

Question 14

Spectrophotometer

Answer 14

shines light through a sample to measure the absorbance of light

*higher the absorbance of light the higher the growth

Question 15

Blank

Answer 15

a tube that contains only growth factor

Question 16

what are 2 examples of genre that form endospores

Answer 16

bacillus and clostridium

Question 17

in what 3 ways does the spore protect dna

Answer 17

• surrounded by thick peptidoglycan and spore coat
• surrounded by acid-soluble proteins
• protected from US radiation

Question 18

What can destory a endospore

Answer 18

autoclaves

sterilizing gases and liquids

ionizing radiation

Question 19

Describe a capsule and how it surrounds the cell

Answer 19

Glycocalyx made of polysaccharides & polypeptides that is well organized tightly bound and surround the bacteria cell.

Question 20

Explain why capsules are consider virulence factors

Answer 20

Because their presence on the bacteria cells increase the chances for serious disease.

Question 21

Describe a biofilm and the role of capsules in their formation. Give an example of a biofilm
that could form in an infection.

Answer 21

Biofilm community of bacteria that stack to a surface.

Biofilm make the bacteria resistant to antibiotics and increased virulence.

Plaque on our teeth is biofilm that can damage the teeth or even kill us if we don’t take care of it.

Question 22

Name an encapsulated bacterial pathogen that is a common cause of pneumonia.

Answer 22

Pneumococcus – Streptococcus pneumoniae.

Question 23

how do flagella cause motility?

Answer 23

the transmembrane electrochemical gradient of ions,

anticlockwise rotation

Question 24

what must be done to see flagella in a microscope?

Answer 24

They have to be thickened with a mordant

Question 25

chemotaxis?

do all bacteria have chemotaxis?

Answer 25

Chemotaxis - direct their movements in response to certain chemicals in their environment

not all bacteria do chemotaxis