Experiment #9: Amines, Amino Acids, And Proteins Flashcards
TERMINOLOGY:
Proteins with 1 peptide chain
Monomeric Proteins
*
TERMINOLOGY:
Proteins with more than 1 polypeptide chain
Multimeric Proteins
TERMINOLOGY:
Only one kind of polypeptide
Homomultimeric
TERMINOLOGY:
Several different kinds of polypeptide chains
Heteromultimeric
TERMINOLOGY:
Each amino acid in a peptide
Moiety or Residue
TERMINOLOGY:
The residue having a free alpha amino group
n-terminal residue
TERMINOLOGY:
The residue having a free carboxyl group
c-terminal residue
SOLUBILITY OF AMINES IN WATER:
Small aliphathic amines whose carbon atoms are less than ________ are water soluble and their solutions gave a ____________ (ph less than 7) when tested with litmus paper
- less than 5
- basic response
TRUE OR FALSE:
Solubility of Amines in Water:
As the number of C atom increase, solubility decreases
TRUE
TRUE OR FALSE:
Solubility of Amines in Water:
Although most amines are not water soluble, amine salts are generally water soluble
TRUE
TRUE OR FALSE:
Solubility of Amines in Water:
The more substituted or larger is the nonpolar group, the more soluble
FALSE; the more substituted/larger the nonpolar group, the less soluble
TRUE OR FALSE:
Solubility of Amines in Water:
The more substituted the compound is, the more basic
TRUE
IDENTIFICATION:
Solubility of Amines in Aqueous Acid:
Amines react with acids forming ____________________ ?
positively charged quaternary amines
Generally used to detect the presence of free alpha amino groups in amino acids, polypeptides, and proteins
Ninhydrin Test
What is the reagent for Ninhydrin Test?
Ninhydrin Solution
What is the positive result for Ninhydrin Test?
Appearance of blue to violet colored spots
The test is used to detect the presence of two or more peptide linkage in proteins and their larger hydrolytic products (proteoses and peptones)
Biuret Test
What is the reagent of Biuret Test?
Alkaline Copper (II) Sulfate
What is the positive result for Biuret Test?
Formation of violet-colored coordination complex due to the coordination of cuptic ions with the unshared electron pairs of the peptide
What is the reagent for Reaction with Lead Acetate?
NaOH/Pb (CH3COO2)
It is a test where the sulfur in sulfur-containing proteins and amino acids can be released as sulfides by the action of strong alkali
Reaction with Lead Acetate
TRUE OR FALSE:
In Reaction with Lead Acetate, the sulfides can be precipitated by lead acetate
TRUE
It is associated with the alteration of the secondary and tertiary structures of biological proteins which results in changes in physical properties and loss of biological activity
Protein Denaturation
TRUE OR FALSE:
Amines are readily protonated by weak acids
FALSE; it is readily protonated by strong acids
*
TRUE OR FALSE:
Protein denaturation may be caused by the action of heat, light, alcohols, strong acids and bases, and other denaturing agents
TRUE
This test is to classify amines where it treat amines with benzenesulfonyl in aqueous sodium hydroxide and then acidified with HCl
Hinsberg Test
What is the positive result for Protein Denaturation?
Appearance of precipitation or coagulated product
IDENTIFICATION:
Amines that are insoluble in pure water will be soluble in acid due to the formation of an _________________?
Ammonium Chloride
