gram-positive vs. gram negative

What are the major structural differences between Gram-positive and Gram-negative bacteria?

cell wall thickness and the presence of an outer membrane

which bacterial group has the thicker peptidoglycan layer?

gram-positive

Which bacterial group has an outer membrane?

gram-negative

Which bacterial group contains teichoic acids?

gram-positive

Which bacterial group contains lipopolysaccharide?

gram-negative

What is the periplasmic space?

the space between the 2 membranes of a gram-negative cell

What are porins?

large protein channels in the LPS of gram negative cells that allow water-soluble molecules to diffuse freely

What is the function of the Gram-negative outer membrane?

LPS is for cell rigidity and stability for protection against chemicals and for immune system evasion

What is lipopolysaccharide?

o-antigen - long sugar chains

What are the three components of LPS?

lipid a, core oligosaccharide, and o-antigen

What is lipid A?

the endotoxin that makes up the inner layer of LPS

What is the core polysaccharide?

core oligosaccharide, sugar chains that provide structural stability

what is the O antigen?

the outer layer of LPS made of repeating sugar chains, this helps the bacteria evade the host’s immune cells

Which component of LPS functions as endotoxin?

lipid a

What type of toxin is LPS?

and endotoxin

Why is Gram-negative bacteria's outer membrane clinically important?

it helps aid the bacteria in evading the host’s immune cells and make them better at resisting antibiotics

Why can Gram-negative bacteria have increased resistance to certain substances?

because the LPS acts as an extra physical and chemical barrier

What are teichoic acids?

where are teichoic acids found?

What structural feature makes Gram-positive cells different from Gram-negative cells?

What would happen to a Gram-positive cell if peptidoglycan cross-linking were blocked?

What would happen to a Gram-negative cell if its outer membrane were damaged?

Given a cell wall diagram, can you identify Gram-positive vs. Gram-negative?

Given a cell wall diagram, can you label the plasma membrane?

Given a cell wall diagram, can you label peptidoglycan?

Given a cell wall diagram, can you label the outer membrane?

Given a cell wall diagram, can you label LPS?

Given a cell wall diagram, can you label the periplasmic space?

Given a cell wall diagram, can you label porins?