Week 9 - Fungi

Question 1

Are fungi chemoorganotrophs or chemolithotrophs?

Answer 1

Chemoorganotrophs.

Question 2

Do fungi have chlorophyll?

Answer 2

No.

Question 3

What is the major sterol in fungal membranes?

Answer 3

Ergosterol.

Question 4

Cryptococcus species are part of phylum Basidiomycota. True or false?

Answer 4

True.

Question 5

Aspergillus and Candida species are part of phylum Zygomycota. True or false?

Answer 5

False, they are part of phylum Ascomycota.

Question 6

Saccharomyces cervisiae is commonly known as:

Answer 6

Baker’s yeast.

Question 7

What is the advantage and disadvantage of S. cervisiae producing alcohol?

Answer 7

It keeps competitors away but involves less efficient energy production.

Question 8

S. cervisiae are carried around by what organisms?

Answer 8

Hornets and wasps.

Question 9

Candida albicans can have multiple morphologies, hence it is:

Answer 9

Polymorphic.

Question 10

C. albicans is a commensal fungus of humans. True or false?

Answer 10

True.

Question 11

Opaque C. albicans cells are better at surviving in the gut. True or false?

Answer 11

False, the skin.

Question 12

Aspergillus species are saprophytic, meaning:

Answer 12

They break down plant material.

Question 13

Where would one commonly find Aspergillus species in domestic settings?

Answer 13

Compost bin.

Question 14

Which genus of yeasts have polysaccharide capsules?

Answer 14

Cryptococcus.

Question 15

Do Aspergillus or Cryptococcus species secrete hydrolases?

Answer 15

Aspergillus.

Question 16

Can superficial fungal infections be fatal?

Answer 16

No.

Question 17

Which fungal species use proteases and ureases to scavenge for nutrients?

Answer 17

Cryptococcus spp.

Question 18

What is the most common fungal pathogen for humans?

Answer 18

Candida albicans.

Question 19

Most people have C. albicans in their gut. True or false?

Answer 19

True, 60%.

Question 20

How is one infected with Aspergillosis?

Answer 20

Inhalation of conidia (spores).

Question 21

How is one infected with Cryptococcosis?

Answer 21

Inhalation of basidiospores.

Question 22

What are the two main human/fungi differences we can exploit for antifungals?

Answer 22

1. Fungi have a cell wall.
2. Fungi use ergosterol.

Question 23

Which class of antifungals directly targets ergosterol?

Answer 23

Polyenes.

Question 24

Which class of antifungals inhibits Erg11 function in ergosterol synthesis?

Answer 24

Azoles.

Question 25

Which class of antifungals inhibits beta-1,3-glucan synthase?

Answer 25

Echinocandins.

Question 26

Which antifungal class is solely fungistatic?

Answer 26

Azoles.

Question 27

If an antifungal doesn’t work on dermatophytes, it would be:

Answer 27

A polyene.

Question 28

If an antifungal doesn’t work on Aspergillus, it would be:

Answer 28

An azole.

Question 29

If an antifungal could kill Candida but only inhibit Aspergillus growth, it would be:

Answer 29

An echinocandin.

Question 30

Which class of antifungal has the lowest toxicity?

Answer 30

Echinocandins.

Question 31

For which class of antifungals are multidrug transporters NOT a resistance mechanism?

Answer 31

Polyenes.

Question 32

What are the three main mechanisms of antifungal resistance?

Answer 32

1. Target alteration/overexpression
2. Upregulation of drug transporters
3. Cellular stress responses

Question 33

Cdr1, Cdr2, Mdr1 - these are all names of what?

Answer 33

Efflux pumps in Candida albicans.

Question 34

Chitin synthesis increases in treated cells, creating thicker cell walls. True or false?

Answer 34

True.