Yeasts and molds (Saccharomyces Cerevisiae)

Question 1

What is a fungus?

Answer 1

Any group of spore-producing organisms feeding on organic matter, including molds, yeast, mushrooms and toadstools,

Question 2

What is a mold?

Answer 2

A fungus that grows in the form of multicellular filaments called hyphae

Question 3

What is a yeast?

Answer 3

A microscopic fungus consisting of single oval cells that reproduce by budding, and are capable of converting surgar into alcohol and carbon dioxide

Question 4

S.Cerevisiae is a species of ____________ yeast

Answer 4

budding

Question 5

In nature Sc is generally found on the surfaces of __________

Answer 5

ripe fruits

Question 6

Sc has _______ chromosomes

Answer 6

16

Question 7

Sc is known for its ability to utilize ________ in formation of ethanol and other by-products

Answer 7

carbohydrates

Question 8

In the Gay-Lussac Equation 180g sugar is converted to ____g Ethanol and ___g CO2

Answer 8

92, 88

Question 9

Sc can exist in both a ________ or a ________ (think of its cell cycle)

Answer 9

haploid, diploid

Question 10

If _____________ are present both haploids and diploids can undergo repeated rounds of vegetative growth and mitosis

Answer 10

adequate nutrients

Question 11

When nutrients become depleted, both haploids and diploids arrest as ______________

Answer 11

stationary phase cells

Question 12

Stationary phase cells are ____________ and __________ distinct from proliferating yeast cells

Answer 12

morphologically and biochemically

Question 13

Stationary phase cells round and bright and contain much higher levels of ____________________ than proliferating cells

Answer 13

storage carbohydrates (trehalose and glycogen)

Question 14

TRUE OR FALSE: Stationary phase cells also have an increased resistance to a number of stresses and environmental conditions when compared to growing cells

Answer 14

TRUE

Question 15

Haploid cells can exist in one of two mating types ______

Answer 15

a or 𝝰

Question 16

Mating type a produce a pheromone _______

Mating type 𝝰 produce a pheromone ______

Answer 16

a factor

𝝰 factor

Question 17

Each cell type has the surface receptor for the __________ mating type. If the surface receptor is stimulated the cells arrest in the _________ of their cell cycle

Answer 17

opposite

G1 phase

Question 18

When the haploid cells arrest in the G1 phase of growth they no longer proliferate but start ________________. The resultant shape is called________

Answer 18

growing towards each other

Shmoo

Question 19

Eventually there is cell contact, _________, and a diploid is formed

Answer 19

fusion

Question 20

Diploid cells that are starved of nitrogen will undergo _________ and ________

Answer 20

meiosis and spore formation

Question 21

4 haploid spores are formed and contained in an _____

Answer 21

ascus, an ascus has even greater resistance to environmental factors than stationary phase cells

Question 22

If the spores are returned to a rich environment they will _________ and _____________ as haploid cells

Answer 22

germinate and commence growth

Question 23

Sc vegetative proliferation occurs via __________

Answer 23

budding

Question 24

The cell cycle comprises several ______________where the progression of the cell cycle is prevented if certain necessary processes have not taken place

Answer 24

checkpoint controls

Question 25

Mitosis will not happen if ______________has not been completed

Answer 25

DNA replication

Question 26

There are several morphogenic aspects of the yeast cell cycle: (name the 4)

Answer 26

1) Bud-site selection: in rich media haploids bud in axial pattern where diploids show polar budding 2) Polarity 3) Pattern 4) Rate of growth

Question 27

Since yeast has a cell wall, growth can only occur where new __________ and cell wall _____________ are delivered.

Answer 27

cell wall material, remodeling enzymes

Question 28

Growing Sc cells ferment _______ via glycolysis to form ethanol. In Stationary phase cells use _________ formed in earlier stages via the TCA and glyoxylate cycles

Answer 28

glucose, the ethanol

Question 29

Most compounds required for Sc metabolism are not able to pass through ___________________, and therefore must be transported via specific transport proteins

Answer 29

the phospholipid membrane

Question 30

________ and _________ are exceptions to this rule and can diffuse easily across the cell membrane

Answer 30

ethanol and glycerol

Question 31

Some carbohydrates, specifically disaccharides, undergo ____________ by secreted _________________, and the resultant hexoses are taken up by the cell

Answer 31

extracellular hydrolysis | invertase or galactosidase

Question 32

____________ is an important carbon source for yeast during brewing and bread-making

Answer 32

Maltose

Question 33

Maltose is actively transported across the cellular membrane, and then hydrolyzed via into two glucose molecules

Answer 33

𝝰-glucosidase (AKA maltase)

Question 34

The cell wall of Sc offers _____________ against physical damage and plays a major role in morphogenesis

Answer 34

mechanical strength

Question 35

___________ compose approximately 50% of the cell wall, while _____________ make up 40% and __________ accounts for the remaining 10%

Answer 35

Glucans mannoproteins Chitin

Question 36

_________ (also known as koji) is used mainly in East Asian cuisine to ferment soy beans, make soy sauce, miso, and break down rice starches into sugars for making sake

Answer 36

Aspergillus oryzae

Question 37

It secretes a selection of ____________ that extracellularly degrade starch to glucose

Answer 37

amylases

Question 38

Name 2 species of amylases

Answer 38

1) endoamylases | 2) exoamylases

Question 39

Aspergillus oryzae: | 1) Conidium 2) Swollen Conidium 3) _____________ 4) ___________

Answer 39

3) germling tube | 4) differentiated hypha

Question 40

A.oryzae is a __________ fungi

Answer 40

filamentous

Question 41

What is a conidium

Answer 41

It is a spore that is produced asexually by A. oryzae fungi at the tip of a specialized hypha that is capable of growing into a new multicellular organism

Question 42

If the conditions are right the conidium will _________ and eventually grow into a ___________ that will eventually form the hyphae

Answer 42

swell | germ tube

Question 43

The ________ are the individual sections that are partitioned by ________ and constitute multicellular filamentous fungi

Answer 43

hyphae | septa

Question 44

how does the grow of fungi occurs

Answer 44

The growth of the fungi occurs via extension of a highly metabolically active hyphal tip

Question 45

There is a ______ located in the middle of each septum that allows for communication between cells

Answer 45

pore

Question 46

What happens if one cell is killed or damaged ? (A.oryzae)

Answer 46

Woronin bodies are grouped near the septum and will plug the pore if it detects cell damage

Question 47

A. oryzae secretes a selection of _________ that extracellularly degrade starch

Answer 47

amylases

Question 48

What is Spitzenkorper in Aspergillus oryzae?

Answer 48

A specific organelle of A.oryzae that is present in the hyphal tip region and is involved in the accumulation and secretion of vesicles that contain secretory enzymes.

Question 49

The secretion vesical is then _________ immediately after fusion with the cell membrane, and is then immediately recycled for incorporation into new secretion vesicles

Answer 49

endocytosed

Question 50

Why is the recycling of secretion vesical important for A.oryzae?

Answer 50

It is critical for sustaining high levels of amylases

Question 51

The ______________ is a special cell that is designed to produce conidium to spread the mold

Answer 51

conidiophore

Question 52

Nutrients are passed from the________ and up to the budding ____________

Answer 52

hyphae, budding

Question 53

When conditions are right the conidium prepares to germinate. The first step is _______

Answer 53

to swell

Question 54

Name 3 other molds:

Answer 54

- Geotrichum candidum - Penicillium candidum - Penicillium roqueforti

Question 55

Geotrichum candidum (name a characteristic)

Answer 55

A rapid growing mold that prevents unwanted mold growth in moist cheeses

Question 56

Penicillium candidum (name a characteristic)

Answer 56

Produces the fuzzy white mold on the surface of bloomy rind cheeses including Brie, Camembert, Coulommiers, and French goat cheeses

Question 57

Penicilium roqueforti (name a characteristic)

Answer 57

Creates the colored veins and surfaces and is a major contributor to the flavor in blue cheeses including Gorgonzola, Roquefort

Question 58

Yeasts and molds provide nutrients to _________

Answer 58

LAB

Question 59

_________ and __________ are anerobic

Answer 59

Molds and AAB

Question 60

___________ and ________ are anaerobic

Answer 60

LAB and yeasts

Question 61

Give a few characteristics of sake :

Answer 61

- Is a traditional Japanese alcoholic drink - Also known as Japanese Rice Wine - Sake generally contains 18-20% ABV (wine is 9-16%, beer is 3-9%) - On special events sake is gently warmed and served in a porcelain bottle or sipped from a porcelain cup - The optimal serving temperature varies by type

Question 62

what do you need to make sake (4)?

Answer 62

water, rice, koji and yeast

Question 63

What is Fukuyama Pot Vinegar?

Answer 63

a traditional Japanese rice vinegar where rice and koji are added without additional organisms to a loosely capped large pot and laid in an open-air field

Question 64

What are the reaction happening in Fukuyama Pot Vinegar?

Answer 64

- Saccharification - Alcohol fermentation - Acetic acid fermentation - Lactic acid fermentation

Question 65

How do you make milk kefir?

Answer 65

beverage milk is inoculated with kefir grains that harbor LAB, AAB, and yeast (and sometimes molds)

Question 66

what is kefiran?

Answer 66

an extracellular polysaccharide that is produced by the LAB found in kefir grains