Final - Unit 1

Question 1

gram-positive cell wall

Answer 1

• purple stain
• thicker cell wall
• fatty acids
• plasma membrane
  
  • membrane protein
  • phospholipid
• membrane protein
• peptidoglycan (majority of cell wall - that’s why it’s so thick)
• teichoic acid

Question 2

gram-negative cell wall

Answer 2

• pink stain
• fatty acids
• plasma membrane
• inner membrane
  
  • membrane protein and phospholipid
• periplasmic space
• peptidoglycan wall
• outer membrane
  
  • murein lipoprotein
  • lipid A
  • O antigen
  • lipopolysaccharide
  • porin

Question 3

describe endospore and its characteristics

Answer 3

• clostridium and bacillus
• do not readily take up stains
• heat is used to facilitate uptake of primary dye by the spore and a counterstain is used to visualize other cells

Question 4

what is the function of a capsule

Answer 4

• it promotes bacterial adhesion to surfaces or interaction with other organisms
• acts as a permeability barrier, as a defense mechanism against phagocytosis and/or as a nutrient reserve
• capsule stain = negative stain = halo

Question 5

what is the function of bacterial cell wall

Answer 5

maintain bacterial cell integrity and shape as well as resist internal turgor pressure