The S (surface) Layer

Question 1

structure of S layer

Answer 1

sheet composed of proteins organized in tetragons or hexagons that surround the cell

Question 2

location of S layer

Answer 2

adheres to OM of gram -ive bacteria and outer surface of peptidoglycan of gram +ive bacteria. under the capsule or slime layer

Question 3

fn of S layer

Answer 3

excludes large molecules but allow cell wall components like teichoic acids and O antigen to go through. and provides protection against Bdellovibrio

Question 4

What is Bdellovibrio

Answer 4

gram -ive vibrio w/a polar flagellum

Question 5

first step in attack by Bdellovibrio in water

Answer 5

using its flagellum, moves rapidly until crashes into prey

Question 6

second step in attack by Bdellovibrio in water (enzymes)

Answer 6

flagellum contd to rotate and w/help of enzymes it bores through prey’s OM

Question 7

third step in attack by Bdellovibrio in water (periplasm)

Answer 7

once in the periplasm, Bdellovibrio damages the Prey’s PM, causing contents of cytoplasm to leak. provides it w/a source of nutrient and nrg

Question 8

fourth step in attack by Bdellovibrio in water (replication)

Answer 8

grows into long filaments, which then divide into individual cells. an unusual method of replication

Question 9

last step in attack by Bdellovibrio

Answer 9

prey is lysed and cells are released