cell structure and Taxonomy

Question 1

what is the main constituent of bacterial cell wall?

Answer 1

peptidoglycan (murein)

Question 2

what does peptidoglycan
(murein) consist of?

Answer 2

Murein = (N-acetyl glucosamine AND N- acetyl muramic acid) + short cross-linked peptide.

Question 3

what color is gram positive bacteria

Answer 3

purple /deep violet (thick cell wall)

Question 4

what color is the gram negative bacteria?

Answer 4

appears in pin/red in gram stain (thin cell wall)

Question 5

what are biofilms and where are they located?

Answer 5

biofilms render the bacteria
more resistant to antibiotics, they are located in the slime layers of glycocalyx

Question 6

Peritrichous

Answer 6

flagella sticking from the whole surface of the bacterial cell.

Question 7

Amphitrichous

Answer 7

flagella sticking from different poles/sides of the bacterial cell.

Question 8

Lophotrichous

Answer 8

a bundle of flagella which stick from only one side of each bacterial cell.

Question 9

Monotrichous

Answer 9

the bacterial cell has one flagellum only.

Question 10

what are spirochetes?

Answer 10

spirally shaped bacteria that use a special type of flagella called ‘axial filaments’
(or endoflagella), such as Treponema Pallidum that cause syphilis.

Question 11

where can you find pili?

Answer 11

in gram-negative bacteria and is thinner than flagella

Question 12

what is the phenetic system of classification?

Answer 12

Grouping organisms according to shared phenotypic features (seen features)

Question 12

what is the phenetic system of classification?

Answer 12

Grouping organisms according to shared phenotypic features (seen features)

Question 13

what is phylogenic system of classification?

Answer 13

Grouping organisms according to genetic relatedness on the evolutionary tree (depends on the genotype).