Gram (-) cell wall differences:
- Large periplasmic space between plasma and outer membranes
- Large amounts of periplasmic enzymes
- Thin peptidoglycan layer
- Contains endotoxin (LPS)
What is lipopolysaccharide made up of?
- Lipid A (highly toxic aspect)
- Core polysaccharide
- O antigen (polysaccharide extends out from core polysaccharide)
Gram (+) cell wall differences:
- Very small periplasmic space w/ very few periplasmic enzymes
- Thick peptidoglycan layer (called murein layer)
- Contains teichoic acids and lipoteichoic acids in peptidoclycan layer
- Large number of exoenzymes that would be periplasmic in Gram (-) bacteria
Periplasmic enzymes:
- Permeases
- Hydrolytic enzymes
What are porins?
Proteins that allow for transport of materials into the cell
What is pseudopeptidoglycan?
A major cell wall structure that looks like peptidoglycan but differs in certain aspects.
What are hopanoids?
Similar to steroids found in eukaryotes and is used to stabilize membranes.
What are archaebacteria?
Transitional organism that is similar to bacteria
Do archaebacteria have peptidoglycan?
No, they have pseudopeptidoglycan
What are Eubacteria?
Means “true bacteria” and is used to differentiate archaea.
Do eubacteria have peptidoglycan?
Yes, because they are true bacteria
What is the Fluid Mosaic model of membrane structure?
The membrane is somewhat fluid d/t the phospholipid bilayer mixed with proteins and glycoproteins.
What are peripheral proteins?
Proteins attached to the surface of the membrane but not imbedded in the membrane.
What are integral proteins?
Proteins that are imbedded in the membrane
Where are glycoproteins attached?
They are covalently bonded to oligosaccharides
Functions of membrane proteins
- nuturient and waste transport
- transport secreted proteins
- carry out metabolic processes
- interactions with environment (ex. chemotaxis receptors)
- flagellar motors
