M7

Question 1

____ and ____ are formed when amino acids are joined together by amide bonds

Answer 1

Peptides and Proteins

Question 2

___ is called also peptide bond

Answer 2

Amide bond

Question 3

___ has 2 amino acids joined together by one peptide bond

Answer 3

Dipeptide

Question 4

___ have many amino acids

Answer 4

Polypeptide

Question 5

___ has more than 40 amino acids

Answer 5

Protein

Question 6

_____ are formed by a condensation reaction

Answer 6

Peptide bonds

Question 7

___ are joined together and water is released

Answer 7

Amino Acids

Question 8

What is the formation of polypeptides?

Answer 8

1. Remove oxygen from the precedent amino acid and two hydrogens from the subsequent amino acid
2. Place the two groups next to each other

Question 9

General test for identification of proteins

Answer 9

Biuret test

Question 10

In the presence of _____ _____, Cu2+ ions forms as a complex with the peptide bonds due to the unshared electron pairs in nitrogen, and the oxygen in water

Answer 10

Alkaline Solution

Question 11

Biuret Test: Gelatin
Result: ?

Answer 11

Purple Solution

Proteins (peptide bonds) are present

Question 12

Biuret Test: Egg Albumin
Result: ?

Answer 12

Purple Solution

Proteins (peptide bonds) are present

Question 13

Biuret Test: Glycine
Result: ?

Answer 13

No Reaction

Question 14

Biuret Test: Antibiotic Solution
Result: ?

Answer 14

Pink Solution

Proteins (peptide bonds) are present

Question 15

Test for the presence of a-amino acids in proteins

Answer 15

Ninhydrin Test

Question 16

___ causes oxidative decarboxylation and deamination of a-amino acids producing an aldehyde, carbon dioxide, and ammonia

Answer 16

Ninhydrin

Question 17

Ninhydrin is reduced to _____ which reacts with the liberated ammonia and another molecule of ninhydrin

Answer 17

Hydrindantin

Question 18

Ninhydrin Test: Egg Albumin
Result: ?

Answer 18

Deep Blue Solution

Presence of alpha-amino acid

Question 19

Ninhydrin Test: Gelatin
Result: ?

Answer 19

No Reaction

Question 20

Ninhydrin Test: Alanine
Result: ?

Answer 20

Deep Blue Solution

Presence of alpha-amino acid

Question 21

Test for the presence of aromatic amino acids

Answer 21

Xanthoproteic Test

Question 22

Amino acids containtin aromatic nucleus react with concentrated HNO3 to from _____-_____ complex on heating.

It changed to ____-____ _____ when excess NaOH is added

Answer 22

Yellow-coloured Complex;

Orange-Red Colour

Question 23

Xanthroproteic Test: Egg Albumin
Result: ?

Answer 23

Dark Yellow Solution

Presence of arom

Question 24

Xanthroproteic Test: Tyrosine
Result: ?

Answer 24

Orange Red Solution

Question 25

Xanthroproteic Test: Alanine Result: ?

Answer 25

No Reaction

Question 26

Xanthroproteic Test: Phenylalanine Result: ?

Answer 26

No Reaction

Question 27

Test for phenolic compounds

Answer 27

Millons Test

Question 28

Millons test is also used to setect the presence of ______ - the only amino acid containing a phrnol group

Answer 28

Tyrosine

Question 29

Tyrosine is the first nitrated by nitric acid in the test solution, then the nitrated tyrosine complexes ______ and ______ in the solution to form either a ______ or _____

Answer 29

Mercury (I) and Mercury (II) Red Precipitated or Red Solution

Question 30

Millon’s Test: Phenol Result: ?

Answer 30

No Reaction

Question 31

Millon’s Test: Phenylalanine Result: ?

Answer 31

No Reaction

Question 32

Millon’s Test: Tyrosine Result: ?

Answer 32

Faint Red Precipitate

Question 33

Millon’s Test: Casein Result: ?

Answer 33

No Reaction

Question 34

Test for the presence of tryptophan

Answer 34

Hopkin’s Cole Test

Question 35

The inly amino acid containing an indole group

Answer 35

Tryptophan

Question 36

The indole reacts with ____ ____ in the presence of a strong acid to form a _____ ______ product

Answer 36

Glyoxylic Acid Violet Cyclic product

Question 37

Hopkins Cole Test: Albumin Result: ?

Answer 37

Violet Ring

Question 38

Hopkins Cole Test: Casein Result: ?

Answer 38

No Reaction

Question 39

Hopkins Cole Test: Gelatin Result: ?

Answer 39

No Reaction

Question 40

Hopkins Cole Test: Tryptophan Result: ?

Answer 40

Violet Ring

Question 41

Test for the presence of cysteine or cystine

Answer 41

Lead Sulfide Test

Question 42

The organic sulfur in cystein or cystine is released as ______ _-_ ____ which from lead sulfide

Answer 42

Inorganic S-8 ions

Question 43

Positive result of Lead Sulfide Test is the formation of ____ / ____ _______

Answer 43

Black or Brown Precipitate

Question 44

Lead Sulfide Test: Albumin Result: ?

Answer 44

Black Solution

Question 45

Lead Sulfide Test: Tyrosine Result: ?

Answer 45

No Reaction

Question 46

Lead Sulfide Test: Casein Result: ?

Answer 46

No Reaction

Question 47

Positive result of Biuret Test

Answer 47

Purple / Pink Solution

Question 48

Positive Result of Ninhyrin Test

Answer 48

Deep Blue Solution

Question 49

Positive result of Xanthroproteic Test

Answer 49

Dark-Yellow / Orange-Red Solution

Question 50

Positive result of Millon’s Test

Answer 50

Red Precipitate or Red Solution

Question 51

Positive Result of Hopkins Cole Test

Answer 51

Violet Ring

Question 52

Positive Result of Lead Sulfide Test

Answer 52

Black / Brown Solution