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Food Science 210 > Microbiology > Flashcards

Flashcards in Microbiology Deck (62)
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1

what are the three outcomes of microbes in food?

pathogenesis, spoilage, preservation

2

What are characteristics of colony morphology? (macroscopic)

form, margin, elevation, size, pigment, optical characteristics, texture

3

what are the major cell morphologies? (microscopic)

cocci, rod (bacillus), spirillum, spirochetes, appendaged, filamentous

4

gram positive stains ___, gram negative stains ___

purple; pink

5

this traps the stain

peptidoglycan

6

what are the 4 phases of bacterial growth?

lag, exponential, stationary, death

7

what is the lag phase?

interval between when culture is inoculated and when growth begins

8

what is the most desirable stage for study of bacteria for enzymes?

exponential phase

9

which phase is associated with waste production?

stationary phase

10

these are highly resistant to heat, easily dispersed, hard to destroy

endospores

11

what are 4 parts of spore?

core, cortex, coat, exosporium

12

outermost layer of spore, thin protein covering

exosporium

13

loosely cross-linked peptidoglycan

cortex

14

contains core wall, cyto membrane, cyto, nucleoid, ribo

core

15

core is high in ____ acid, and ____ proteins

dipicolinic; small acid soluble

16

cytoplasm in endospore core contains ___% of water found in vegetative cell, pH is __ unit lower

10-25; 1

17

examples of bacteria that don't form spores

e coli and s. aureus

18

molds multiply by spores known as ___

conidia

19

these can't be cultured on plates and must be detected directly; single celled eukaryotes

protozoan parasites

20

obligate parasites that are host specific, transmitted fecal/orally

food borne virus

21

sources of microbes in food?

soil/water, plants, food utensils, GI, mamary tissue, food handlers, animal feed, animal hide, air/dust

22

biggest source of microbes in foods?

soil and water

23

fresh cut meats have ___ cells/gram microbes, comminuted (ground up) meats have ____ cells/gram

10^3; 10^6

24

contamination occurs primarily during ___

harvesting

25

____ can eliminate pathogens

composting

26

raw milk typically has ______ cfu/mL bacteria

100-100 000

27

alpha 1-4 polymers of galacturonic acid

pectin

28

beta 1-4 glucose polymers

cellulose

29

alpha 1-6 glucose polymers that alter texture/flavour (slime)

dextrans

30

do microbes target proteins or carbs first?

carbs