biochem pre lab 3

Question 1

Protein comes from the Greek word

Answer 1

Proteios which “means first of importance.”

Question 2

It is considered a protein when it has at least 1___ amino acid residues. Otherwise, it is known as a 2__________

Answer 2

1 50, 2 Peptide

Question 3

Proteins assume a three-dimensional structure known as their ____________

Answer 3

native conformation

Question 4

________ refers to the disruption and unfolding of proteins, thus losing their biological activity

Answer 4

Denaturing

Question 5

For example, when a white solid from an egg converts from transparent liquid to white solid clumps, it is called __________.

Answer 5

coagulation

Question 6

_______ _______ are generally defined as metals with relatively high densities, atomic weight, or atomic number

Answer 6

Heavy metals

Question 7

______ ____ is an acid derived from one or more inorganic compounds.

Answer 7

Mineral acid

Question 8

2 tests that help in the precipitation of proteins by strong mineral acid

Answer 8

Heller’s test
Robert’s test

Question 9

________ ______ are high molecular weight anions

Answer 9

alkaloidal reagents

Question 10

three procedures for the precipitation of protein

Answer 10

precipitation of protein by strong mineral acid
precipitation of protein by Heavy Metal Salts
precipitation of protein by alkaloidal reagents

Question 11

_______ is the sticking of molecules together to form a solid that will come out of the solution

Answer 11

Precipitation

Question 12

A ______ _______ is a chemical reaction that is used to transform colorless chemical compounds into colored derivatives which can be detected visually

Answer 12

Color reaction

Question 13

The 1______ Test, also known as 2________ test, is a general test for the presence of proteins which is dependent on the presence of peptide bonds

Answer 13

Buiret Test, Piotrowskis test

Question 14

A positive result for the Buiret Test or Piotrowskis test

Answer 14

Violet color, if it contains peptides, proteoses, and peptones, a minimum of 2 peptide bonds

Question 15

_______ test is a general test for the presence of proteins, which is dependent on the presence of free alpha amino groups.

Answer 15

Ninhydrin test

Question 16

Ninhydrin test:
Free alpha-amino groups of proteins and amino acids undergo an ________ _________ with ninhydrin

Answer 16

oxidative determinant

Question 17

A positive result for the Ninhydrin test

Answer 17

Presence of diketohydrin, a color complex that is also known as Ruhemans purple. (Deep blue or violet color)

Question 18

The __________ test is used to indicate the presence of amino acids containing phenyl (benzene ring), namely phenylalanine, tyrosine, and tryptophan

Answer 18

Xanthropethic test

Question 19

Xanthropethic test:
The rings phenylalanine, tyrosine, and tryptophan undergo 1_______ with treatment with 2________ _____ _____ when heated

Answer 19

1 Nitration,2 concentrated nitric acid

Question 20

A positive result for the Xanthropethic test

Answer 20

(Yellow to orange color)

Question 21

________ reaction is a specific test for the presence of the amino acid tryptophan

Answer 21

Adamkiewicz reaction

Question 22

A positive result for the Adamkiewicz reaction

Answer 22

Formation of violet ring

Question 23

Adamkiewicz test:
The ______ group reacts with the glyoxylic acid in the presence of concentrated sulfuric acid

Answer 23

indole

Question 24

______ ______test is a specific test for the presence of amino acid cysteine.

Answer 24

Reduced sulfur test

Question 25

A positive result for the Reduced sulfur test

Answer 25

Lead sulfide (black precipitate.)

Question 26

______ proteins contain only amino acid components

Answer 26

simple proteins

Question 27

1________ proteins contain amino acids and non-amino acids called 2______ groups

Answer 27

1 conjugated, 2 prosthetic

Question 28

___________ test is a general test for the presence of carbohydrates in a solution

Answer 28

molisch’s test

Question 29

molisch’s test:
A protein with a carbohydrate prosthetic group is known as ________

Answer 29

Glycoproteins

Question 30

A positive result for the molisch’s test test

Answer 30

Violet ring

Question 31

________ ________ test is a test for finding a phosphate moiety.

Answer 31

Modified Numans

Question 32

Modified Numans:
A conjugated protein containing a phosphate group is called a ____________

Answer 32

phosphoprotein

Question 33

A positive result for the Modified Numans test

Answer 33

A canary yellow precipitate of ammonium phosphomolybdate