Lec 2

Question 1

What is the cell envelope?
A. Cell membrane
B. Cell wall
C. Both
D. None

Answer 1

Cell membrane and cell wall (C)

Question 2

Bacteria do not contain mitochondria so how bacteria produce energy?

Answer 2

By Kreps cycle , glycolysis, and oxidative phosphorylation

Question 3

Where do Krebs cycle and glycolysis occur?

Answer 3

Cytosol

Question 4

Where does oxidative phosphorylation (electron transport chain) occur?

Answer 4

On plasma membrane

Question 5

In the cell wall of gram positive and negative do plasma membrane occur?

Answer 5

True

Question 6

In the cell wall of gram positive and negative do they both have an outer membrane?

Answer 6

False only gram negative

Question 7

What is the function of the cell membrane?

Answer 7

It gives the bacteria cell rigidity, protection from osmotic lysis

Question 8

What is the difference between gram positive and negative in relation to the cell wall?

Answer 8

1. Gram positive have peptidoglycan thicker than gram negative
2. In gram negative it have two periplasmic space but gram positive have one periplasmc space
3. Gram negative have lipoprotein that connect the peptidoglycan to the outer membrane

Question 9

The outer membrane contains lypopolysaccharide and porin. What is the function of porin?

Answer 9

Act like a gate that regulate the chemicals that enter in and out the cell

Question 10

Why gram positive do not include lipoprotein?

Answer 10

Cause it does not have the outer membrane

Question 11

Heat is the main structure that makes gram negative indotoxin?

Answer 11

Lipopolysaccharides

Question 12

Gram positive have in its cell wall peptidoglycan, teichoic acid, lipoteichoic acid, and few proteins
Explain each component and function?

Answer 12

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

Question 13

What is the name of the lipoprotein that is in gram negative?

Answer 13

Braun’s lipoprotein BLP

Question 14

What are the 4 parts of lipopolysaccharide?

Answer 14

O-antigen, polysaccharide, disaccharide diphosphate, fatty acids

Question 15

Does lipid A occur in gram positive?

Answer 15

Never

Question 16

The tails of the lipopolysaccharide is what? And what’s its main purpose?

Answer 16

The tails are fatty acids and this is the actual part that make the gram negative endotoxin

Question 17

Where does the secretory devices occur and what is the function?

Answer 17

They are in the periplasmic space and they help transporting the material.

Question 18

What does peptidoglycan/ murein/ lactam contain?

Answer 18

Composed of alternating residue of sugars and amino acids

Question 19

What are the residue of sugar that are in the peptidoglycan?

Answer 19

N-acetylglycosamine NAG
N-acetylmuramic acid NAM

Question 20

Each NAM is connecting with?

Answer 20

Peptide chain and they are cross liked with peptide linkage

Question 21

What is the linkage between NAM and NAG?

Answer 21

Glycosidic linkage

Question 22

What are the tetra peptide that are linked to NAM?

Answer 22

L- alanine , D- glumatic acid, L- lysine(gram positive) diaminopimelic acid(gram negative), D- alanine

Question 23

What are the virulence factors?

Answer 23

Capsule , biofilms, pili, flagellum, proteins

Question 24

What are the types of flagella?

Answer 24

Monotrichous flagella, lophotrachous flagella, amphitrichous flegella, peritrichous flagella.

Question 25

Plasmids Cary genes coding for?

Answer 25

Pathogens and virulence factors , antibiotic resistance factors, bacterial replication