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Flashcards in Bacteria Introduction Deck (8)
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1

What colour do Gram positive bacteria stain?
What colour do Gram negative bacteria stain?

Purple
Red/pink

2

Differentiate Gram positive from negative in terms of membranes

Positive have a plasma membrane and a peptidoglycan
Negative have an additional periplasmic space and a lipopolysaccharide

3

Describe how to carry out Gram staining

Heat fixation of the sample to a glass slide
Add crystal violet and Gram's iodine (purple, complex formed)
Add acetone (negative decolourise - LPS dissolves)
Add secondary stain (colourless become red/pink)

4

Outline the range of flagellum types a bacterial cell may have

Monotrichous - one
Lopho - many from one point
Amphi - both sides
Peri - all over

5

What is meant by conjugation in term of bacteria?

Plasmid transfer from one bacterium to another

6

What 3 ways does genetic variation occur in bacteria?

Conjugation
Transformation (taken from dead)
Transduction (phage DNA infection)

7

Describe the 2 ways a bacteriophage is formed?

Lysogenic cycle - DNA injection and integration
Lytic cycle - no integration/replication of pathogenic/lysis

8

How does PCR work?

Genetic amplification of bacterial gene sequencing giving a unique pattern of bands
(akin to gel electrophoresis)