BIOCHEM LABORATORY

Precipitation and Coagulation

What are the two tests to isolate proteins from samples?

Native Confirmation

Proteins assume a specific three-dimensional structure called __

Globular (spherical)

The native confirmation of Albumin is __

Fibrous (elongated)

The native confirmation of Gelatin is __

Denaturation

This is the change in protein native conformation; the disruption and unfolding of protein

Reversible and Irreversible

What are the two types of denaturation?

Coagulation

This refers to the clumping of particles together in a solution

Alcohol and Heat

What are the two causes of coagulation?

Coagulum

What is the result of coagulation?

Solids clumping together

What is the appearance/result of coagulation?

Ethanol and Heating

These materials were used to observe the coagulation of egg albumin

Precipitation

The refers to the sticking of molecules together to form a solid that
will come out from the solution

Heavy metals, Strong mineral acids, and Alkaloidal reagents

What are the causes of precipitation in egg albumin?

Coagulation by Heat/Alcohol

This result is due to?

Precipitation by Heavy Metal Salts

This is a result due to?

Silver Nitrate (AGNO3)

The reagent used for this test is?

Precipitation by Heavy Metal Salts

This is a result of?

Cupric Sulfate (CuSO4)

The reagent used for this test is?

Precipitation by Strong Mineral Acids

This is a result of?

Heller’s Test

The test for this reaction is called?

Nitric Acid (HNO3)

What reagent was used for this test?

Precipitation by Strong Mineral Acids

This is a result of?

Robert’s Test

The test for this reaction is called?

Conc. Nitric Acid + Sat. Magnesium Sulfate (HNO3 + MgSO4)

What reagent was used for this test?

Precipitation by Alkaloidal Reagents

This is a result of?

Picric Acid

The reagent used for this test is?

Precipitation by Alkaloidal Reagents

This is a result of?

Tannic Acid

The reagent used for this test is?

Color Reaction

This is a chemical reaction that is used to transform colorless chemical compounds into colored derivatives which can be detected visually.

Biuret Test

This is a test for peptide bonds.

Positive

Biuret Test:
Is this a positive or negative result?

Negative

Biuret Test:
Is this a positive or negative result?

Ninhydrin Test

This is a test for proteins based on free alpha amino groups.

Positive

Ninhydrin Test:
Is this a positive or negative result?

Negative

Ninhydrin Test:
Is this a positive or negative result?

Xanthroproteic Test

This is a test for phenyl-containing amino acids.

Phenyl-containing Amino Acids

What does this test indicate?

Adamkiewicz Test

This is a test for the presence of tryptophan.

Tryptophan

What does this test indicate?

Reduced Sulfur Test

This is a test for the presence of cysteine.

Cysteine

What does this test indicate?

Molisch Test

This is a test for the presence of carbohydrates in solution.

Carbohydrates

What does this test indicate?

Diluted Sodium Hydroxide (NaOH)

Among these reagents, which is yeast RNA fully soluble with?

Hot Water

Among these reagents, which is yeast RNA slightly soluble with?

Cold Water, 95% Ethanol, Hydrochloric Acid (HCl)

Among these reagents, which is yeast RNA insoluble with?

Sulfuric Acid (H2SO4)

What solution is needed for yeast RNA hydrolysis?

Test for Purine

Tests for the Chemical Component of Nucleic Acids:
Based on the result, which test is this?

Ammoniacal Silver Nitrate (Ammoniacal AgNO3) + Concentrated Ammonium Hydroxide (NH4OH)

Tests for the Chemical Component of Nucleic Acids:
What reagent(s) was/were needed to fulfill this test?

Test for Pentose

Tests for the Chemical Component of Nucleic Acids:
Based on the result, which test is this?

Molisch Reagent + Concentrated Sulfuric Acid (H2SO4)

Tests for the Chemical Component of Nucleic Acids:
What reagent(s) was/were needed to fulfill this test?

Test for Phosphate

Tests for the Chemical Component of Nucleic Acids:
Based on the result, which test is this?

Ammonium Hydroxide (NH4OH) + Nitric Acid (HNO3) + Ammonium Molybdate
((NH4)2Mo7O24)

Tests for the Chemical Component of Nucleic Acids:
What reagent(s) was/were needed to fulfill this test?