Microbio Ch. 2

Question 1

What is Morphology?

Answer 1

The study of the form of things.

Question 2

Coccus

Answer 2

Spherical/Ovoid

Question 3

Bacillus

Answer 3

Rod/Cylindrical

Question 4

Spirochete

Answer 4

Flexible spiral

Question 5

Spirillum

Answer 5

Rigid coil or curved cell, usually flagellated

Question 6

Strepto

Answer 6

Chains

Question 7

Staphylo

Answer 7

Irregular clusters

Question 8

Diplo

Answer 8

Pairs

Question 9

Tetrad

Answer 9

Square (4-cells)

Question 10

Sarcina

Answer 10

Cubes (8-cells)

Question 11

Vibrio

Answer 11

Curved, comma shaped cell

Question 12

What is Arrangement?

Answer 12

When cells remain grouped/clustered after division

Question 13

Only higher level arrangements with cells are which?

Answer 13

• Cocci

- Bacilla

Question 14

Bacterial Cytoplasmic Membrane

Answer 14

• Phospholipid bilayer
• Integral membrane proteins
• Peripheral membrane proteins
• Hopanoids (sterol-like molecules)

Question 15

.

Answer 15

Cholesterol does not exist in bacterial cytoplasmic membrane

Question 16

Archaeal Membranes

Answer 16

• Bacteria and Eukarya have “ester” linkages
• Ether linkages in phospholipids of Archaea
• Arachael lipids have isoprenes instead of fatty acids

Question 17

.

Answer 17

Know the difference of which domain has which linkage

Question 18

What are the two main groups of species of Bacteria?

Answer 18

• Gram-negative cell wall

- Gram-positive cell wall

Question 19

Gram-negative cell wall

Answer 19

• 2 membranes surrounding thin peptidoglycan
• outer membrane contains LPS (lipopolysaccharide) and porin proteins
• Endotoxin: lipid A, the tocix component of LPS

Question 20

Gram-positive cell wall

Answer 20

• One cytoplasmic membrane with peptidoglycan
• 90% peptidoglycan
• Common to have teichoic acids (acidic substances) covalently bound to peptidoglycan
• Most digestion is extracellular

Question 21

Structure of Peptidoglycan

Answer 21

• Rigid layer

- Can be destroyed by lysozyme

Question 22

What are the 3 components of LPS?

Answer 22

• Core polysaccharide
• O-polysaccharide
• Lipid A

Question 23

Periplasm.

Answer 23

• Space located between cytoplasmic and outer membranes
• ~15 nm wide
• Houses many extracellular proteins (enzymes)

Question 24

Porins

Answer 24

Transmembrane protein channels for entrance and exit of solutes.

Question 25

Which prokaryotes lack cell walls?

Answer 25

- Mycoplasma - Thermoplasma Instead, they have cytoplasmic membranes.

Question 26

Facts about Archaean Cell Walls

Answer 26

- No peptidoglycan | - Pseudomurein

Question 27

Facts about Pseudomurein

Answer 27

- Composed of NAG and NAM | - Cannot be destroyed by lysozymes and penicillin

Question 28

S-Layers.

Answer 28

- Common cell walls in Archaea - Paracrystalline structure - Always outermost layer - Consists of proteins or glycoproteins

Question 29

Capsule and Slime Layers

Answer 29

- Not considered part of the cell wall due to no significant structural strength - Polysaccharide layers - Capsule: if tightly attached, tight matrix; visible with India Ink - Slime layer: loosely attached, easily deformed, often involved in biofilms

Question 30

What are the functions of Capsules and Slime Layers?

Answer 30

- Assist in attachment to surfaces - Develop and maintain biofilms - Virulence factors: protects against phagocytosis - Prevent dehydration/dessication

Question 31

What is the function of Fimbriae?

Answer 31

Enable organisms to stick to surfaces or form pellicles (thin sheets of cells on a liquir surface).

Question 32

What are the different type of Pili?

Answer 32

- Conjugative/Sex Pili | - Type IV Pili

Question 33

What is the function of Conjugative/Sex Pili?

Answer 33

Facilitate genetic change between cells.

Question 34

What is the function of Type IV Pili?

Answer 34

Adhere to host tissues and support twitching mobility.

Question 35

Facts about Cell Inclusions.

Answer 35

- Function as energy reserves and carbon reservoirs - Enclosed by thin membrane - Reduce osmotic stress - Carbon storage polymers - Magnetosomes, sulfur globules, polyphosphate granules, gas vesicles, carbonate materials

Question 36

Facts about Endospores.

Answer 36

- Formed during sporulation - Resistant to heat, harsh chemicals, and radiation - Dormant, survival structures to endure unfavorable growth conditions - Ideal for disperal via wind, water, or animal gut - Present only in some gram-positive bacteria

Question 37

Formation and Granulation of Endospores

Answer 37

- Sporulation: Vegetative cell converted to non-growing | - Germination: Re-emergence under favorable conditions often triggered by presence of water

Question 38

Structure and Features

Answer 38

- Many layers: Exosporium (outermost), spore coats, cortex, core - Contains dipicolinic acid - Enriched Ca2+ - Core contains small acid-soluble spore proteins (SASP), which bind and protect DNA and function as carbon and energy source for outgrowth

Question 39

What components are flagella made of?

Answer 39

- Basal body - Hook - Filament