Bacterial Cell Wall

Question 1

What are the major functions of the bacterial cell wall?

Answer 1

~Protection from osmotic changes.
~Determination and maintenance of cell shape.

Question 2

BACTERIAL cell walls are made of

Answer 2

Peptidoglycan

Question 3

Peptidoglycan has a

Answer 3

Polysaccharide portion and peptide portion

Question 4

The polysaccharide is a complex

Answer 4

Polymer consisting of alternating monosaccharides called (NAG) and (NAM)

Question 5

Gram-positive cell wall consist of

Answer 5

~Many layers of Peptidoglycan surrounding the plasma membrane
~tectonic acids and lipotechoic acids

Question 6

The gram negative cell wall are

Answer 6

~More complex
~Consists of only a single of Peptidoglycan surrounding the plasma membrane and outer membrane

Question 7

The outer membrane is phospholipid like the plasma membrane, but also contains

Answer 7

~Lipoprotein- which anchor it to the cell wall and plasma membrane
~Lipopolysaccharide (which contain Lipid A, an endotoxin, and O polysaccharide, an antigen)
~Porin proteins- allows transport of small hydrophilic molecules across the outer membrane

Question 8

Outer membrane structures and functions

Answer 8

~Protects cell by excluding large toxic molecules
~Creates a periplasmic space
~No techoic acids

Question 9

Gram-negative cell walls

Answer 9

~are susceptible to mechanical breakage that gram-positive ones
~are more successful in avoiding poor osmotic conditions.

Question 10

Cell walls can be damaged by

Answer 10

~Lysozyme-enzyme that breaks down glycosidic bonds between NAG and NAM
Penicillin-an antibiotic that interferes with the cell wall synthesis by inhibiting peptide bridge formation p

Question 11

Major functions of plasma membrane

Answer 11

~Delineates cell boundary, and hold in the contents
~To control transportation of substances into and out of the cell