28 Questions
Which component provides strength to bacterial cell walls?
Peptidoglycan
What is the function of lysozyme in bacterial cell walls?
Hydrolyzes peptidoglycan
Which type of cell walls have teichoic acids and are thicker?
Gram-positive
What do Archaeal cell envelopes lack?
Peptidoglycan
In which type of cell envelopes is the lipopolysaccharide layer found?
Gram-negative
What is the function of Lipid A in lipopolysaccharide?
Acts as an endotoxin
Where are hydrolytic enzymes and transport proteins located in bacterial and archaeal cells?
Periplasm
What is the function of porins in the outer membrane of bacterial and archaeal cells?
Transport small hydrophilic molecules
What provides strength and protection to bacterial and archaeal cells?
S-layer
What is the main function of transport proteins in bacterial and archaeal cells?
Move solutes against concentration gradient
What is the primary function of the cell wall in bacterial and archaeal cells?
Prevent lysis
What classification system distinguishes bacteria as Gram-positive or Gram-negative?
Gram staining
What is the function of bacterial capsules and slime layers?
Assist in attachment to surface, role in development and maintenance of biofilms, contribute to infectivity, prevent dehydration/desiccation
What are the functions of pili and fimbriae in bacteria?
Facilitate genetic exchange between cells, stick to cell surface or biofilms
What do inclusion bodies in bacteria store?
Carbon storage polymers, polyphosphate, sulfur, and other minerals
What is the purpose of gas vesicles in floating cells?
Control buoyancy in the water column
What is the function of magnetosomes in magnetotactic bacteria?
Act as an internal magnet to orient within magnetic field
What are endospores in bacteria?
Specialized spores – survival structures to endure unfavorable growth conditions
What is the purpose of cell motility in microbes?
To find food or run away from hostile environments
What is the function of flagella in bacteria?
For propulsion
What is the purpose of chemotaxis in bacteria?
Directed movement in response to chemicals
What happens to bacterial cells in the absence of a chemical gradient during chemotaxis?
They move in a random fashion
What is the purpose of measuring chemotaxis in bacteria using a capillary tube?
To screen nutrients for their preference by bacteria
What is the purpose of sense attractants and repellents with chemoreceptors in E. coli?
To respond to chemicals
What is the function of the cytoplasmic membrane?
Permeability barrier for polar and charged molecules
What type of linkage is present in the phospholipids of archaea?
Ether linkage
Which structure confers structural strength to prokaryotic cells?
Cell wall
What type of proteins are embedded in the cytoplasmic membrane?
Integral membrane proteins
Study Notes
Bacterial and Archaeal Cell Envelope Structures
- Transport proteins move solutes against concentration gradient
- Cell wall withstands osmotic pressure to prevent lysis
- Gram staining classifies bacteria as Gram-positive or Gram-negative
- Peptidoglycan provides strength to bacterial cell walls
- Lysozyme hydrolyzes peptidoglycan in bacterial cell walls
- Gram-positive cell walls have teichoic acids and are thicker
- Archaeal cell envelopes lack peptidoglycan and may have S-layer or pseudomurein
- Gram-negative cell envelopes have lipopolysaccharide layer
- Lipid A in lipopolysaccharide is an endotoxin
- Periplasm contains hydrolytic enzymes and transport proteins
- Porins in outer membrane transport small hydrophilic molecules
- S-layers provide strength and protection to bacterial and archaeal cells
Test your knowledge of bacterial and archaeal cell envelope structures with this quiz. Learn about transport proteins, cell wall composition, Gram staining, peptidoglycan, lipopolysaccharide, periplasm, and S-layers.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
