lecture 1

Question 1

gram-stain

Answer 1

a differential staining procedure that stains cells either purple (gram-positive cells) or pink (gram-negative cells)

Question 2

gram-positive

Answer 2

a bacterial cell whose cell wall consists chiefly of peptidoglycan; it lacks the outer membrane of gram-negative cells

Question 3

gram-negative

Answer 3

a bacterial cell with a cell wall containing small amounts of peptidoglycan and an outer membrane

Question 4

peptidoglycan

Answer 4

a polysaccharide composed of alternating repeats of N-acetylglucosamine and N-acetylmuramic acid arranged in adjacent layers and cross-linked by short peptides; a component of the cell envelope of virtually all bacteria

Question 5

teichoic acid

Answer 5

a phosphorylated polyalcohol found in the cell wall of some gram-positive bacteria

Question 6

outer membrane

Answer 6

a phospholipid- and polysaccharide containing unit membrane that lies external to the peptidoglycan layer in cells of gram-negative bacteria and is a component of the cell envelope in these organisms

Question 7

lipopolysaccharide (LPS)

Answer 7

a combination of lipid with polysaccharide and protein that forms the major portion of the outer membrane in gram-negative bacteria