Lec 2 Flashcards
What is the cell envelope?
A. Cell membrane
B. Cell wall
C. Both
D. None
Cell membrane and cell wall (C)
Bacteria do not contain mitochondria so how bacteria produce energy?
By Kreps cycle , glycolysis, and oxidative phosphorylation
Where do Krebs cycle and glycolysis occur?
Cytosol
Where does oxidative phosphorylation (electron transport chain) occur?
On plasma membrane
In the cell wall of gram positive and negative do plasma membrane occur?
True
In the cell wall of gram positive and negative do they both have an outer membrane?
False only gram negative
What is the function of the cell membrane?
It gives the bacteria cell rigidity, protection from osmotic lysis
What is the difference between gram positive and negative in relation to the cell wall?
- Gram positive have peptidoglycan thicker than gram negative
- In gram negative it have two periplasmic space but gram positive have one periplasmc space
- Gram negative have lipoprotein that connect the peptidoglycan to the outer membrane
The outer membrane contains lypopolysaccharide and porin. What is the function of porin?
Act like a gate that regulate the chemicals that enter in and out the cell
Why gram positive do not include lipoprotein?
Cause it does not have the outer membrane
Heat is the main structure that makes gram negative indotoxin?
Lipopolysaccharides
Gram positive have in its cell wall peptidoglycan, teichoic acid, lipoteichoic acid, and few proteins
Explain each component and function?
Teichoic acid is a repeated unit of pentose sugar , it strengthens cell wall and calcium ion sequestration
Lipoteichoic acid it is lipid linked teichoic acid, activator of the immune system
What is the name of the lipoprotein that is in gram negative?
Braun’s lipoprotein BLP
What are the 4 parts of lipopolysaccharide?
O-antigen, polysaccharide, disaccharide diphosphate, fatty acids
Does lipid A occur in gram positive?
Never
The tails of the lipopolysaccharide is what? And what’s its main purpose?
The tails are fatty acids and this is the actual part that make the gram negative endotoxin
Where does the secretory devices occur and what is the function?
They are in the periplasmic space and they help transporting the material.
What does peptidoglycan/ murein/ lactam contain?
Composed of alternating residue of sugars and amino acids
What are the residue of sugar that are in the peptidoglycan?
N-acetylglycosamine NAG
N-acetylmuramic acid NAM
Each NAM is connecting with?
Peptide chain and they are cross liked with peptide linkage
What is the linkage between NAM and NAG?
Glycosidic linkage
What are the tetra peptide that are linked to NAM?
L- alanine , D- glumatic acid, L- lysine(gram positive) diaminopimelic acid(gram negative), D- alanine
What are the virulence factors?
Capsule , biofilms, pili, flagellum, proteins
What are the types of flagella?
Monotrichous flagella, lophotrachous flagella, amphitrichous flegella, peritrichous flagella.
Plasmids Cary genes coding for?
Pathogens and virulence factors , antibiotic resistance factors, bacterial replication
