Bacterial Structure and Organization Quiz

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What is the general organization of a bacterial cell?

Cell membrane and cytoplasm (correct)

Cell membrane, cytoplasm, and flagella

Cell wall, cytoplasm, and pili

Cell membrane, cell wall, and capsule

Which bacterial structure is responsible for protecting the cell from lysis due to changes in osmotic pressure?

Flagella

Periplasm

Pili/fimbriae

Capsule (correct)

What is the main function of the bacterial cell wall?

Provide structural support and shape to the cell (correct)

Facilitate cellular locomotion

Regulate the entry of nutrients into the cell

Facilitate genetic exchange between cells

Which component of the bacterial cell envelope is associated with adherence to host cells and tissues?

Pili/fimbriae (B) Signup and view all the answers

What is the function of the plasma membrane in bacteria?

Barrier against aqueous ions (B) Signup and view all the answers

What is the main function of peptidoglycan?

Structural support and shape (A) Signup and view all the answers

Where is cardiolipin found in bacteria?

In the plasma membrane (D) Signup and view all the answers

Which components of the bacterial cell wall differ between different types and species of bacteria?

Peptidoglycan layer (B) Signup and view all the answers

What is the main function of the outer membrane in Gram-negative bacteria and Chlamydiaceae?

Selective barrier and protection against lysis (C) Signup and view all the answers

What is present in the outer leaflet of the outer membrane?

Lipopolysaccharide (LPS) (D) Signup and view all the answers

How does the outer membrane contribute to host mimicry and antigenic variation?

Via sugars (O-antigen) and proteins (D) Signup and view all the answers

What is the function of the periplasm in bacteria?

Protection against osmotic lysis via solutes (C) Signup and view all the answers

What is the major function of capsules in bacteria?

Antiphagocytic activity (B) Signup and view all the answers

Which component is responsible for adhesion to surfaces and biofilm formation in bacteria?

Slime (A) Signup and view all the answers

What is the main function of pili/fimbriae in bacteria?

Adhesion to host cell receptors (B) Signup and view all the answers

What is the role of the 'K' antigen in some serotyping schemes of bacteria?

Vaccine target (D) Signup and view all the answers

Which drug prevents the recycling of bactoprenol-PP during peptidoglycan synthesis?

Bacitracin (C) Signup and view all the answers

What is inhibited by Fosfomycin during peptidoglycan synthesis?

MurA (C) Signup and view all the answers

Which drug inhibits alanine racemase and D-ala-D-ala synthetase during peptidoglycan synthesis?

Cycloserine (A) Signup and view all the answers

What does Tunicamycin prevent during peptidoglycan synthesis?

NAM-P to Und-P transfer (D) Signup and view all the answers

Which antibacterial enzyme cleaves the bond between NAG and NAM in peptidoglycan?

Lysozyme (C) Signup and view all the answers

What is the primary function of the plasma membrane in bacteria?

Control over osmotic balance (B) Signup and view all the answers

Which component forms a 3D multilayered net in the peptidoglycan structure?

Peptide tail (A) Signup and view all the answers

What is the role of cardiolipin in the plasma membrane of bacteria?

Barrier against aqueous ions (D) Signup and view all the answers

Where is the outer membrane absent in some genera or species of bacteria?

Gram-positive bacteria (D) Signup and view all the answers

What type of bacteria has a variable outer membrane structure used for differentiating strains or species?

Gram-negative bacteria (D) Signup and view all the answers

What is added in phase II of PG biosynthesis in the presence of a bridge peptide?

Pentaglycine bridge (A) Signup and view all the answers

Where does monomer production for PG biosynthesis occur?

Cytoplasm (C) Signup and view all the answers

What is used for the production of many extracellular polysaccharides in phase I of PG biosynthesis?

Bactoprenol-PP (C) Signup and view all the answers

What is responsible for incorporating the new monomer into the PG macromolecule in phase III of PG biosynthesis?

Transglycosylases (C) Signup and view all the answers

Which type of drug inhibits transpeptidases and leads to cell lysis as autolysins continue to function by weakening the new peptidoglycan?

$\beta$-lactams (penicillins, cephalosporins, etc.) (D) Signup and view all the answers

Which of the following bacterial genera is Gram-negative?

Salmonella (B) Signup and view all the answers

What is a characteristic feature of the outer membrane of Gram-negative bacteria?

Containment of crystal violet during Gram staining (B) Signup and view all the answers

Which type of bacteria has a cell wall structure that includes mycolic acids?

Mycobacterium (D) Signup and view all the answers

Which staining technique is specifically used for acid-fast bacteria?

Ziehl-Neelsen stain (D) Signup and view all the answers

Which bacterial genus is known for its resistance to chemicals and antibiotics due to its unique cell wall components?

Bacteroides (D) Signup and view all the answers

What is the main function of Penicillin-binding proteins (PBPs) in the peptidoglycan (PG) biosynthetic process?

Cleaving PG crosslinks to allow cell growth and separation (A) Signup and view all the answers

Which bacteria have an outer membrane with lipopolysaccharides (LPS) but no peptidoglycan (PG)?

Chlamydia and Chlamydophila (A) Signup and view all the answers

What is the main role of the protein layer in the context of bacterial cell wall biosynthesis?

Providing structural support to the bacterial cell wall (B) Signup and view all the answers

Why is the Gram stain not useful for visualizing spirochetes such as Treponema and Borrelia?

They have a very thin structure that is not visible by light microscopy (D) Signup and view all the answers

Which enzyme is responsible for removing the last D-alanine from peptide tails that have not been crosslinked in peptidoglycan (PG)?

DD-carboxypeptidase (C) Signup and view all the answers

What is the main function of peptidoglycan in bacteria?

Protection against osmotic lysis (A) Signup and view all the answers

Which statement best describes the biological effects of peptidoglycan?

Unique to bacteria and induces cytokines (C) Signup and view all the answers

What role do teichoic and lipoteichoic acids play in Gram-positive bacteria?

Regulation of autolysis (B) Signup and view all the answers

Which bacterial component is involved in adherence to host cells and tissues?

Peptidoglycan (B) Signup and view all the answers

What is the general role of adhesins in bacteria?

Facilitating adherence to host cells and tissues (A) Signup and view all the answers

Which component is a specific type of peptidoglycan fragment targeting ciliated respiratory epithelial cells?

Cytotoxin (B) Signup and view all the answers

What is the primary effect of teichoic and lipoteichoic acids in Gram-positive bacteria?