Structure of Bacteria

Question 1

What are the different cell morphology?

Answer 1

• Coccus
• Spirochete
• Rod
• Budding and appendages bacteria
• Spirillum
• Filamentous bacteria

Question 2

What shape is coccus ?

Answer 2

Spherical shaped bacteria

Question 3

What is an example of rod-shaped bacteria?

Answer 3

E.coli

Question 4

What shape is spirillum bacteria?

Answer 4

Curved shaped bacteria

Question 5

What shape is spirochete?

Answer 5

Cork screw shaped bacteria

Question 6

How do measure cell size?

Answer 6

Surface area to volume ration

Question 7

Does a larger S:V ratio have a faster or slower uptake of nutrients?

Answer 7

Faster

Question 8

What does the cell wall of animal cells consist of?

Answer 8

Phospholipid bilayer, interspersed wit protein

Question 9

What does the cell wall of plant cells consist of?

Answer 9

Phospholipid bilayer, mesh of cellulose surrounding it

Question 10

What does the cell wall of bacterial cells consist of?

Answer 10

Gram-negative and Gram-positive both have phospholipid bilayer but differ in many ways

Question 11

What is a cytoplasmic membrane?

Answer 11

Phospholipid bilayer - 1 glycerol attached via 2 hydroxyl groups to 2 fatty acids

Question 12

How do phospholipid differ in characteristics?

Answer 12

Different molecules attached to polar head of another hydroxyl on the glyceral

Question 13

What adds strength to a cytoplasmic membrane?

Answer 13

Hopanoids

Question 14

What are essential for mycoplasmas?

Answer 14

Sterols

Question 15

Why are sterols essential for mycoplasma?

Answer 15

Strengthen cell wall in bacteria

Question 16

What bond do bacteria and eukary have in the phospholipid bilayers?

Answer 16

Ester linkage

Question 17

What bond do archaea have in phospholipid bilayer?

Answer 17

Ether linkage

Question 18

Describe the phospholipid bilayer of an archaea:

Answer 18

• Repeating units of isoprene
• Linked to form phytanyl
• 2 phytanyl can join at each other ends to form diglycerol tetraethers

Question 19

What is better by having repeating units of isoprene in archaea than fatty acids in Bactria and eukary?

Answer 19

More robust
More stronger
Suit harsh conditions

Question 20

What are peptidoglycan made up of?

Answer 20

N-acetylglucosamine
N-acetylmuramic acid
forms a tetra peptide

Question 21

What are the N-acetylglucosamine and N-acetylmuramic acid bonded together by?

Answer 21

Glycosiding bond at B1,4 linkage

Question 22

How much does peptidoglycan make up of the cell wall in Gram-positive bacteria?

Answer 22

90%

Question 23

How much does peptidoglycan make up the cell wall in Gram-negative bacteria?

Answer 23

10%

Question 24

What links the two tetrapeptides in a Gram-positive bacteria?

Answer 24

Pent-glycine bridge (DAP — d-Ala)

Question 25

What links the two tetrapeptides in a Gram-negative bacteria?

Answer 25

Covalently bonded

Question 26

What is peptidoglycan?

Answer 26

Mesh like layer which protects a bacteria cytoplasmic membrane

Question 27

What type of Gram has a second bilayer?

Answer 27

Gram-negative

Question 28

How is the second phospholipid bilayer in a gram-negative organised?

Answer 28

Asymmetrical

Question 29

What does the second phospholipid bilayer in a gram negative consist of?

Answer 29

- O antigens - Interspaced with proteins, porins - Large polysaccharide components

Question 30

What are O antigens?

Answer 30

Carbohydrate structure: | O-polysaccharides, corepolysaccharides and lipid A

Question 31

Why do you phospholipid bilayer is have porins?

Answer 31

Allows transfer of molecules across a lipid bilayer

Question 32

How do you describe bacteria with O-antigens?

Answer 32

Smooth bacteria

Question 33

How do you describe bacteria without O-antigens?

Answer 33

Rough bacteria

Question 34

What is the structure of a Gram-positive bacteria?

Answer 34

Large peptidoglycan | Phospholipid bilayer

Question 35

What is the structure of a Gram-negative bacteria?

Answer 35

Small peptidoglycan | 2x phospholipid bilayer

Question 36

Give three cell surface structures of bacteria:

Answer 36

- Capsules - Fimbriae and pili - Flagellar

Question 37

Describe a capsules:

Answer 37

- Can be polysaccharides or proteins | - role in pathogenesis and biofilm formation

Question 38

Describe fimbriae and pili:

Answer 38

- proteinaceous, can be glycosylated - role in pathogenesis, biofilms and conjunction - Involved in twitching motility

Question 39

What can a pilus be used for?

Answer 39

Transferring DNA from one cell to another

Question 40

Describe a flagella:

Answer 40

Multimeric protein complex traversing both inner and outer membranes

Question 41

What are the different localisation of flagella?

Answer 41

- Peritrichous - Polar - Lophotrichous - Amphitrichous

Question 42

How can bacteria move?

Answer 42

Using a flagella

Question 43

How many times per second is the flagella rotating?

Answer 43

100 rotations per second

Question 44

What is a reversible flagellum?

Answer 44

Flagellum can rotate in counterclockwise (Moves forwards) or clockwise (moves backwards)

Question 45

What occurs to the cell is a bacteria that has a bundle of flagellum rotating counterclockwise direction?

Answer 45

Cell moves forwards

Question 46

What happens if a bacteria has a bundle of flagellum which is rotating clockwise?

Answer 46

Bundle unravels and bacteria tumbles and turns – allows bacteria to move towards optimum environment

Question 47

What are the components of a flagellum?

Answer 47

Helical filament and basal body connected by a hook

Question 48

The hook in the flagellum is it flexible or constricted?

Answer 48

Flexible

Question 49

A flagellum has a MS ring where is it located?

Answer 49

Cytoplasmic reticulum

Question 50

A flagella has a C ring where is it located?

Answer 50

Cytoplasm

Question 51

What type of rings are present in a gram negative flagellum?

Answer 51

L and P ring

Question 52

What do L and P rings do you in gram negative flagellum?

Answer 52

Guide spinning rod through cell (do not spin)

Question 53

Why does a gram positive bacteria have no L and P rings in their flagellum?

Answer 53

Lack of outer membrane

Question 54

What is the role of Mot protein surrounded by an inner ring in the flagellum?

Answer 54

Anchors flagellum in cytoplasmic membrane

Question 55

What is the role of Fli protein in the flagellum?

Answer 55

Axis motor switch via reversing the direction of rotation of flagellum

Question 56

What are motors powered by?

Answer 56

Energy from protein gradient

Question 57

Where does the protein gradient that powers the motor exist across?

Answer 57

Cytoplasmic membrane

Question 58

How does the proton gradient provide energy for the motor of a flagellum?

Answer 58

- Proton concentration higher in periplasmic space than inside cell - electrons flow down electrochemical gradient - release energy as a flow

Question 59

What the movement turns MS and C rings and rod in flagellum?

Answer 59

The movement of protons