P2. PROTEINS

Question 1

complex macromolecule made up of amino acids.

Answer 1

Proteins

Question 2

the 20 amino acids varies in…

Answer 2

numbers & sequence

Question 3

Amino Acids contains what groups?

Answer 3

COOH [carboxyl group]
-NH2 [amino group]
-R group [the side chain]

Question 4

the building block of proteins?

Answer 4

amino acids

Question 5

2 types of test used in Proteins?

Answer 5

Biuret Test
Hopkin Cole’s Test

Question 6

• general test/semi-quantitative test.
• test for the detection of peptide bonds/peptide linkages

Answer 6

Biuret Test

Question 7

Cupric ions [in an alkaline medium] forms a violet complex with [nitrogen] peptide bonds in the protein.

Answer 7

Biuret Test

Question 8

TRUE OR FALSE?
All proteins contain peptide linkages.

Answer 8

True

Question 9

Reagents used in Biuret Test:

Answer 9

10% NaOH
Copper Sulfate

Question 10

The violet positive result in biuret test indicates a percentage of what?

Answer 10

5% Albumin

Question 11

TRUE OR FALSE:
COLOR REACTION in Biuret Test depends on the presence peptide bonds/linkages.

Answer 11

True

Question 12

DARKER COLOR in Biuret test means?

Answer 12

MANY PEPTIDE LINKAGES

Question 13

LIGHTER COLOR in Biuret test means?

Answer 13

FEW PEPTIDE LINKAGES

Question 14

Pink color in the Biuret Test means?

Answer 14

their is a presence of peptide linkages.

Question 15

UREA & ALANINE in Biuret Test results?

Answer 15

no visible reaction/
no visible result

Question 16

• indole ring of tryptophan combines with aldehydes

e.g formaldehyde in the presence of conc. Sulfuric acid to form a violet-colored compound

Answer 16

Hopkin’s Cole Test

Question 17

Reagents used in Hopkin’s Cole Test:

Answer 17

Hopkin Cole’s Reagent

Question 18

Composition of Hopkin’s Cole Rgt.:

Answer 18

Formaldehyde
Mercuric Sulfate
Sulfuric Acid

Question 19

chemical composition of the Hopkin’s Cole Rgt. that causes a MILD OXIDATION of indole group of tryptophan [which condenses w/ aldehyde to give a colored complex].

Answer 19

Mercuric Sulfate

Question 20

Result of Hopkin’s Cole Test: It forms a ____ and a ____ forms at the junction of the two layers.

Answer 20

1. separate layer
2. deep violet or purple ring

Question 21

if there is a purple ring, there is a?

Answer 21

tryptophan

Question 22

• there is a presence of indole ring in its structure
• the only one who will give a deep violet/purple ring because they have an indole group

Answer 22

Tryptophan

Question 23

Substances in Hopkin’s Cole Test wherein TRYPTOPHAN IS ABSENT:

Answer 23

Albumin
Gelatin
Tyrosine

Question 24

Results of Albumin, Gelatin, and Tyrosine in Hopkin’s Cole test:

Answer 24

• (-) indole ring
• no visible result/ no visible reaction