Bacteria Structure And Function

Question 1

What are the two main types of bacterial cell walls?

Answer 1

Gram-positive and Gram-negative

Question 2

What separates the inner and outer cell walls in Gram-negative bacteria?

Answer 2

Periplasmic space

Question 3

What is the primary component of the Gram-positive bacterial cell wall?

Answer 3

Peptidoglycan layer

Question 4

What additional substances can be found in the Gram-positive cell wall?

Answer 4

• Teichoic acid
• Teichuronic acid
• Various polysaccharides

Question 5

What is the function of the cell membrane in bacteria?

Answer 5

• Selective permeability
• Electron transport chain in energy generation
• Receptor site for antigen binding
• Location of enzymes
• Mitosis

Question 6

What does peptidoglycan provide to bacterial cells?

Answer 6

• Shape
• Rigidity
• High osmotic pressure maintenance

Question 7

What is the composition of the cytoplasm in bacteria?

Answer 7

• Ribosomes
• Granules (glycogen, starch, sulfur, fat, polyphosphate)
• Enzymes (hydrolytic, polymerases)
• Water and ions
• Macromolecules (lipids, structural proteins, carbohydrates)

Question 8

What is the ribosome size in bacteria?

Answer 8

70S

Question 9

What are the two subunits of bacterial ribosomes?

Answer 9

• 50S
• 30S

Question 10

What is the shape of bacterial nucleoid?

Answer 10

Scattered throughout the cytoplasm

Question 11

What type of DNA do eubacteria possess?

Answer 11

Double stranded circular DNA in haploid form

Question 12

What is the role of DNA gyrase in bacteria?

Answer 12

Keeps DNA in supercoiled state

Question 13

What distinguishes Gram-negative bacteria from Gram-positive bacteria?

Answer 13

Thinner peptidoglycan layer and presence of periplasmic space

Question 14

What are the components of the bacterial flagella?

Answer 14

• Basal body
• Hook
• Filament

Question 15

What is the function of pili in bacteria?

Answer 15

Attachment and conjugation

Question 16

What is endotoxin primarily composed of?

Answer 16

Lipid A (part of lipopolysaccharides)

Question 17

What type of bacteria produce exotoxins?

Answer 17

Both Gram-positive and Gram-negative organisms

Question 18

What is a capsule in bacterial cells?

Answer 18

A well-defined layer external to the cell wall, composed of polysaccharides or polypeptides

Question 19

What is the difference between a protoplast and a spheroplast?

Answer 19

• Protoplast: Gram-positive bacteria with loss of cell wall
• Spheroplast: Gram-negative bacteria with loss of cell wall

Question 20

Which bacteria are known for forming spores?

Answer 20

• Clostridium spp.
• Bacillus anthracis

Question 21

What are Mycoplasmas?

Answer 21

Cell wall-less bacteria

Question 22

What are the major categories of pathogenic bacteria?

Answer 22

• Gram-negative bacteria with cell walls
• Gram-positive bacteria with cell walls
• Cell wall-less bacteria
• Archaeobacteria

Question 23

What is the significance of the high osmotic pressure in bacteria?

Answer 23

It necessitates a rigid cell wall to prevent osmotic lysis

Question 24

Fill in the blank: The cell membrane is composed of a _______.

Answer 24

Lipid bilayer

Question 25

True or False: All bacteria have a cell wall.

Answer 25

False