Question

29) The peptidoglycan chain is made up of polymers of a) alanine and glycine b) cytosine and guanine e) glucose and ribose d) ATP and protein N-acetylmuramic acid and N-acetylglocosamine 30) Safranin is a counterstained used in the gram stain procedure because a) cells will not stain gram positive without it b) safranin accentuates the gram positive stain the gram negative cells will be unstained otherwise d) the purple color is hard to see in the microscope e) all of the above 31) The acid fast stain reacts with: a) a cell wall protein b) a plasma membrane protein c) a cell wall lipid d) a plasma membrane lipid e) a cytoplasmic carbohydrate 32) Nucleotides within the same strand of DNA are held together by: a) covalent bonds b) hydrogen bonds c) ionic bonds d) all of the above e) none of the above 33) If a major molecule of the cell contains the atoms, C, N, O, and H, it may a) protein b) carbohydrate c) lipid d) nucleic acid e) a and d 34) If a major macromolecule of the cell contains P, it may be: a) membrane lipid b) carbohydrate c) water d) nucleic acid

Answer 1

29)) e - peptidoglycan chain is made up of nacetyl glycosamine and n acetyl muramic acid. Both these are held together by covalent chain and form glycan chain

30) c. Saffranin is counterstain used for both gram positive and gram negative and endospore staining .it is classic stain which stains both gram positive and negative.

31) c -- acid fast microorganisms contains large amount of lipid in their cell wall Eg mycolic acid which resist staining by ordinary method like gram stain

32) a - nucleotide within same strand of DNA are held together by phoshodiester bond which is a covalent bond while h bond formed between opposite strand.

33) e - a and d

protein and nucleic acid contains C , H, N, O atoms but N is absent in both carbohydrate and lipids

34) d

major macromolecule which contains P is nucleic acid only. While lipid have C, H, O and same atoms are present in carbohydrate and water contains H and O