biolab midterms Flashcards
CH(NH2)COOH
Protein that consists of amino acids
(?) link to each other when the carboxyl group of one molecule reacts with the amino group of another molecule.
Amino acids
Basic building blocks of enzymes, hormones, proteins, and body tissues.
Amino acids
compound consisting 2 or more amino acids.
Peptide
have 10 or fewer amino acids.
Oligopeptides
Peptides consisting more than 50 amino acids
Proteins
Used for quantitative photometrical determination of total protein concentration. (Intensity of color that is produced)
Biuret Test
Peptides and protein react with Cu2+ (Copper Iron) in alkalinity to create a (?)
blue violet color.
Peptides and protein react with (?) in alkalinity to create a blue violet color.
Cu2+ (Copper Iron)
Using (?) the aromatic rings of amino acids like tyrosine and tryptophan are nitrated.
65% Nitric Acid
Nitro derivates show intensely (?)
yellow color.
Biochemical test for the detection of amino acids containing aromatics
Xanthoproteic test
Used to detect presence of soluble proteins
Millon’s Test
Reddish-brown coloration or precipitate indicates the presence of tyrosine residue (Occurs in nearly all proteins)
Millon’s Test
Sulfur-containing amino acids when boiled converts into an inorganic sulfide (Na2S, Sodium Sulfide) - Reacts with lead acetate to form a (?) - Cysteine and Cystine give positive result to the sulfur test.
black precipitate of PbS (Phosphate-Buffered Saline)
(?) containing amino acids when boiled converts into an inorganic sulfide (Na2S, Sodium Sulfide) - Reacts with lead acetate to form a black precipitate of PbS (Phosphate-Buffered Saline) - Cysteine and Cystine give positive result to the sulfur test.
Sulfur
● Test for indole ring of tryptophan condensed with glyoxylic acid in the presence of sulfuric acid ● Forms violet-colored complex
Hopkins-Cole Test
When it reacts with Ninhydrin, a (?) complex is formed.
Test is given by ALL proteins
purple-blue
disruption and possible destruction of both the secondary and tertiary structure.
Denaturation of Protein
The (?) remains the same after the denaturation process.
primary structure
Occurs between amide groups in the secondary protein structure
Hydrogen Bonding
occurs in tertiary protein structures - In a variety of amino acid combinations
Hydrogen Bonding
(?) denatures proteins by disrupting the side chain intramolecular hydrogen bonding.
Alcohol
Gets disrupted by the addition of alcohol.
Hydrogen Bonding
- Used as a disinfectant for the skin
70% Alcohol
- Concentration of alcohol is able to penetrate the bacterial cell wall and denature the proteins and enzymes inside the cell wall.
70% Alcohol
- Merely coagulates the protein on the outside of the cell wall
95% Alcohol
- Prevents alcohol from entering the cell
95% Alcohol
(?) can be used to disrupt hydrogen bonds and non-polar hydrophobic interactions. increases kinetic energy and cause molecules to vibrate rapidly causing bond disruption.
Heat
Heat can be used to disrupt (?). - Heat increases kinetic energy and cause molecules to vibrate rapidly causing bond disruption.
hydrogen bonds and non-polar hydrophobic interactions
Heat increases (?) and cause molecules to vibrate rapidly causing bond disruption.
kinetic energy
● Tannate and Trichloroacetate are high molecular weight anions
● Negative charge of anions counteracts Positive charge of amino group in proteins, giving precipitate.
Alkaloidal Reagents
(?) are high molecular weight anions
Tannate and Trichloroacetate
Negative charge of anions counteracts Positive charge of amino group in proteins,
giving (?)
giving precipitate.
● Disrupt salt bridges
Inorganic Acids
● Result from the neutralization of an acid and amine on side chains.
Salt Bridges
- ionic between positive ammonium group
- ionic between negative acid group
Positive interaction
(?) disrupt salt bridges held together by ionic charges.
Inorganic acids
Inorganic acids disrupt salt bridges held together by (?)
ionic charges.
● Occurs when positive and negative ions in the salt change partners with the positive and negative ions in the new acid.
Double Replacement Reaction
● Occurs in the digestive system, where acidic gastric juices cause the coagulation of milk
Double Replacement Reaction
● Distribution of the solute between a polar liquid phase
● Strongly absorbed on the cellulose fibers of paper
● Moves up the paper, amino acid is carried to a particular position on paper.
Paper Chromatography
- Depends on properties such as molecular weight, structure, shape, and polarity of the molecule
The relative affinity
Higher affinity for mobile phase than stationary phase
- Travels with solvent - Unimpeded by filter paper
Amino Acid Affinity
- Tends to stick to paper
- Travels more slowly than the solvent front.
Higher affinity for paper than the solvent
An (?) that is highly soluble in the eluting solvent will have a higher affinity for the mobile phase than an amino acid that is less soluble in the solvent.
amino acid
Ninhydrin reacts with amino acids to form a (?)
blue-violet compound
The (?) defines the ratio of the distance moved by a particular component divided by the distance moved by the solvent
Rf value
(?) and (?) give positive result to the sulfur test
cysteine and cystine
