Flashcards
Lab Practicum 2: Exercise 9
Cards in this deck (14)
- 1capsulesticky outer-most layer external to the outer-membrane (if any) or cell wall (if any). Provides protection by prevention from phagocytosis and provides adherences to surfaces. Doesn't stain (chargeless, neutral, non-ionic). Cannot be heat-fixed, distorts/destroys the capsule. Water-soluble--can be rinsed out
- 2Virulencedisease-causing ability of an organism (extent of its pathogenicity)
- 3structural stainsstains the structure; used to observe endospores, flagella, and capsules, for example
- 4endosporethick-walled, protective, non-vegetative, resting cell that forms inside a bacterial cell during a deficiency of nutritional resources to ensure survival of the bacteria by being resistant to heating, certain chemicals, and harsh environmental conditions. It exists in a dormant state and does not reproduce.
- 5explain how the presence of a capsule contributes to its virulence(i) prevents phagocytosis
(ii) allows attachment to surfaces - 6why can't capsules e stained by ordinary methods?chargeless (does not pick up stains because stains are cationic/anionic). distorted in heat, and are water-soluble (rinsed out with water)
- 7how does one resolve this staining dilemma with capsules?(i) negative stain first to prevent morphological distortion from heat-fixing
(ii) simple stain - 8what is the 1st and foremost step in spore staining?steam bath to penetrate endospore's thick coat
- 9primary stain in spore stainingmalachite green
- 10decolorizer used in spore stainingwater
- 11vegetative cell's color after applying water in spore staining; endospore's color after applying water in spore stainingcolorless; green
- 12counterstain in spore stainingsafranin
- 13vegetative cell's color after applying safranin in spore stain; endospore's color after applying safranin in spore stainred/pink; green
- 14why are endospores difficult to stain?outer covering composed of keratin, consequently making it "tough as nails"
Information
- Description
- Flashcards on Lab Practicum 2: Exercise 9, created by newsha on 22/10/2014.
- Created by
- newsha
- Views
- 16
- Rating