Bio lab

• The increase in temperature disrupts the intermolecular hydrogen bonds. and hydrophobic interactions of proteins, lowering the rate of atoms' vibrations.

  False - vibrations are increased
• Organic solvent, e.g., ethanol, disrupts the intermolecular hydrogen bonding of the secondary and tertiary structure of albumin.


  True
• Heavy metal ions, e.g., Cu2+, Ag+, and Pb2+, precipitate proteins from the solution because proteins become cross-linked by these heavy metals.


  True
• The addition of NaOH disrupts albumin's hydrogen bonds, leading to denaturation; hence, more precipitate was observed.


  True
• HCI was added to acidify the albumin solutions. Exposure to strong acids will disrupt albumin's hydrogen bonds, resulting in denaturation.


  True
• The positive result in Millon's test on the precipitate from the salting-out process indicates the presence of tyrosine.


  True
• In the Salting out Process, the solubility of albumin decreases when the solution is saturated with ammonium sulfate.


  True
• Peptone is pink with biuret reagent, which confirms the presence of peptide linkages in its structure.


  True
• Peptones are precipitated from the solution by partial saturation with ammonium sulfate. At the same time, proteoses fail to react even when fully saturated with ammonium sulfate.


  False - proteoses are precipitated from solution by half saturation with ammonium sulfate, while peptones don't react even with fully saturated ammonium sulfate.
• Albumin is denatured when heated.


  True
• The source of nitrogen in the Nitrogen test is the soda lime.


  True
• Seliwanoff's test confirms the presence of aldoses.

  False - Both
• An alkaline environment is required for Moore's test.


  True
• Tollen's Phloroglucin reaction is a test confirming the presence of sugars with a free aldehyde.

  False - It's a test to distinguish pentoses and hexoses
• Coagulation is a reversible process that is maximum at the isoelectric pH of protein


  False - Irreversible.
• Sulfur in casein was precipitated as

  barium sulfate3 multiple choice options
• The components of soda lime are sodium hydroxide and?

  calcium oxide3 multiple choice options
• What substance in casein was tested by charring?

  C3 multiple choice options
• What was the chemical formula of the gas released during the test for the

  presence of nitrogen in casein?

  NH33 multiple choice options
• The formation of water droplets when casein was heated in a test tube

  indicates the presence of

  H3 multiple choice options
• Adding concentrated nitric acid to the filtrate from the heated casein + fusion

  mixture converted P to


  PO4^3-3 multiple choice options
• What process is involved in adding concentrated nitric acid to the filtrate from the heated casein + fusion mixture converted P to Phosphate

  oxidation3 multiple choice options
• The color of the resulting precipitate in the positive test for sulfur in casein is

  white3 multiple choice options
• The chemical formula of the precipitate that took form in the positive test for P is.


  (NH4)3PO4.12M0033 multiple choice options
• What is the color of carbon?

  black3 multiple choice options
• The color of the precipitate in the positive test for P is

  yellow3 multiple choice options
• What color indicates a positive result in the Biuret test for proteins?

  Deep Violet3 multiple choice options
• What protein-containing substance was tested in Experiment 2?

  Albumin3 multiple choice options
• What test detects the presence of phenyl group in proteins?

  Xanthoproteic3 multiple choice options
• What is the role of the concentrated HNO3 in adding concentrated nitric acid to the filtrate from the heated casein + fusion mixture converted P to Phosphate

  Oxidizing Agent3 multiple choice options
• The following are color reactions of proteins EXCEPT

  Thymol test3 multiple choice options
• The test for proteins used to detect the presence of phenol group

  Millon's Test3 multiple choice options
• What indicates a positive result in the Xanthoproteic test for proteins?

  Formation of a dark yellow or orange precipitate3 multiple choice options
• What specific protein test uses 0.5% copper sulfate and 10% sodium hydroxide as reagents?

  Biuret Test3 multiple choice options
• Which groups will give a positive result in the Xanthoproteic

  reaction test?

  Tyrosine, tryptophan, and phenylalanine3 multiple choice options
• What amino acid will give a positive result with Millon's test?

  Tyrosine3 multiple choice options
• Which test utilizes mercury and concentrated nitric acid as the reagents?

  Millon's3 multiple choice options
• What observable result indicates a positive reaction has occurred in the

  Glyoxylic acid reaction test for proteins?

  Formation of violet ring3 multiple choice options
• This test is used to detect the presence of albumin in urine

  Heller's Ring Test3 multiple choice options
• Another name for Glyoxylic Acid Reaction is

  Hopkins-Cole3 multiple choice options