yeast and mold

Question 1

Saccharomyces cerevisiae

Answer 1

budding yeast species

• yeasts are known as “sugar molds”
• single cell
• cannot be airborne (needs a vector)
• 16 chromosomes

Question 2

Gay-Lussac Equation

Answer 2

reaction describing the metabolic process of yeast

glucose is converted to 2ethanol and 2carbon dioxide

Question 3

Is Sc haploid or diploid?

Answer 3

can be either

If there is adequate nutrients both haploid and diploid cells can grow in the vegetative state or undergo mitosis

Question 4

*stationary phase cells

Answer 4

• morphologically and biochemically different distinct from proliferating yeast cells.
• Contain much higher concentrations of storage carbohydrates (glycogen, trehalose)
• increased resistance to stresses and environmental conditions

Question 5

what are the 2 mating types of haploid yeast cells?

Answer 5

alpha and a
alpha produce the pheromone alpha factor
a produce the pheromone a factor
-each binds to a receptor located on the opposite type of cell

Question 6

When do diploid yeast cells undergo meiosis

Answer 6

when they are starved of N

Question 7

How are diploid yeast cells formed?

Answer 7

1. receptor is stimulated
2. cells arrest in the G1 stage
3. cells begin to grow towards one another forming a shmoo
4. when the cells contact there is fusion and a diploid cell is formed

Question 8

ascus

Answer 8

4 haploid cells are contained in an ascus, which has even greater resistance to stressors and environmental factors than stationary cells

Question 9

how do yeast cells bud?

Answer 9

haploid: on the same side
diploid: opposite sides

Question 10

what metabolisms of yeast occur in the stationary phase?

Answer 10

cells use the ethanol formed in earlier stages via TCA and glyoxylate cycles

Question 11

What metabolisms of yeast occur in the proliferating state?

Answer 11

fermentation of sugars to ethanol and CO2

Question 12

are compounds needed for Sc metabolisms easily transported across the membrane?

Answer 12

NO, they need transporters
Exceptions: ethanol and glycerol
sometimes extracellular disaccharides are hydrolyzed outside the cell, so they can be transported inside the cell

Question 13

What is the metabolism of maltose?

Answer 13

• maltose breaks down into 2 glucose by maltase (alpha glucosidase)
• maltose is transported across the membrane

Question 14

invertase

Answer 14

hydrolyzes sucrose into fructose and glucose

Question 15

what material gives the cell wall its strength?

Answer 15

chitin

Question 16

Aspergillus Oryzae

Answer 16

used to ferment soy beans, make soy sauce, and break down rice starches

Question 17

How does Aspergillus Oryzae break down starch

Answer 17

starch is broken down into glucose via amylase

Question 18

*condidium

Answer 18

spore produced asexually capable of growing into a multicellular organism

Question 19

*germ tube

Answer 19

conidium swells into a germ tube, which eventually forms hyphae

Question 20

*pore

Answer 20

septums separate the cells of the hyphae. Pores are located in the middle of each septum, which allow the cells to communicate with each other

Question 21

*Woronin bodies

Answer 21

group near the septum and plug the pore if the cell detects damage

Question 22

*hyphae

Answer 22

constitute the multicellular filamentous fungi

Question 23

*setum

Answer 23

separates the cells of the hyphae

Question 24

Spitzenkorper

Answer 24

located at the hypae tip. involved in the accumulation and secretion of vesicles that contain secretory enzymes
secretory vesicles are then recycled/endocytosed.

Question 25

conidiopore

Answer 25

produce conidium to spread the mold. Nutrients are passed through the fungi and stored in the budding conidium