Gram-Negative

Question 1

The main component of a bacterial cell wall is peptidoglycan which is made of cross linked _ and _

Answer 1

The main component of a bacterial cell wall is peptidoglycan which is made of cross linked N-acetyl muramic acid (NAM) and N-acetyl glucosamine (NAG)

Question 2

Gram-negative bacteria has a (thinner/thicker) peptidoglycan layer; they have an additional periplasmic space before the peptidoglycan layer and an additional impermeable _ layer

Answer 2

Gram-negative bacteria has a thinner peptidoglycan layer; they have an additional periplasmic space before the peptidoglycan layer and an additional impermeable outer membrane layer
* The outer membrane has LPS
* Porins are present to facilitate diffusion of nutrients

Question 3

_ in the outer membrane allow hydrophilic soultes to be transported to and from the cell via diffusion

Answer 3

Porins in the outer membrane allow hydrophilic soultes to be transported to and from the cell via diffusion

Question 4

The LPS contains three components:
1. _
2. _
3. _

Answer 4

The LPS contains three components:
1. Lipid A: the toxic portion which anchors the molecule to the phospholipid layer
2. A core polysaccharide: composed of 10-15 sugars
3. O antigen: species specific

Question 5

LPS can help to evade the immune system by manipulating the host cells’ sialic acid, which makes the cells _

Answer 5

LPS can help to evade the immune system by manipulating the host cells’ sialic acid, which makes the cells antiphagocytic

Question 6

The _ portion of LPS is what allows our immune system to recognize which gram-negative bacteria is present; it is composed of 2-5 sugars repeated up to 25 times

Answer 6

The O antigen portion of LPS is what allows our immune system to recognize which gram-negative bacteria is present; it is composed of 2-5 sugars repeated up to 25 times

Question 7

Monocytes and macrophages have receptors _ and _ which bind to lipid A –> inflammatory response

Answer 7

Monocytes and macrophages have receptors TLR4 and CD14 which bind to lipid A –> inflammatory response
* Macrophages induce TNF-a, IL-1, IL-6, nitric oxide, complement, etc

Question 8

Exotoxins commonly have an A subunit for _ and a B subunit for _

Answer 8

Exotoxins commonly have an A subunit for toxicity and a B subunit for adherence to host cells

Question 9

Adherence factors like pili and fimbriae give the bacterial cell an overall (hydrophobic/hydrophilic) surface to better adhere to human cells

Answer 9

Adherence factors like pili and fimbriae give the bacterial cell an overall hydrophobic surface to better adhere to human cells