Biomolecule Identifying Tests

Question 1

What does the Sudan test look for?

Answer 1

Lipids

Question 2

What result does dark red on the Sudan test indicate?

Answer 2

Negative for lipids

Question 3

What a result of two layers of light red and red indicate on the Sudan test?

Answer 3

Positive for lipids

Question 4

What is the Biuret test used to detect?

Answer 4

Proteins

Question 5

What does purple on the Biuret test indicate?

Answer 5

Positive for proteins

Question 6

What does blue on the Biuret test indicate?

Answer 6

Negative for proteins

Question 7

What is the Bradford protein assay?

Answer 7

Quantitatively determines how much protein is present with Coomassie Brilliant Blue dye

Question 8

What is the Ninhydrin test used to detect?

Answer 8

Amino acids based on presence of carboxyl groups of proteins peptides

Question 9

What does purple on the Ninhydrin test indicate?

Answer 9

Positive for amino acids

Question 10

What does yellow on the Ninhydrin test indicate?

Answer 10

Positive for proline

Question 11

What does blue on the ninhydrin test indicate?

Answer 11

Negative

Question 12

What is the Benedict’s test used to detect?

Answer 12

Reducing sugars (all monosaccharides bearing aldehyde groups in open form)

Question 13

What does blue on the Benedict’s test indicate?

Answer 13

0% reducing sugars

Question 14

What does Lugol’s iodine solution test indicate

Answer 14

Starch

Question 15

What color is a positive Lugol’s solution test

Answer 15

Dark blue/black

Question 16

What does a dark blue/black lugol’s solution test indicate

Answer 16

Positive for starch

Question 17

What color is a negative Lugol’s solution test

Answer 17

Reddish orange

Question 18

What does a reddish orange lugol’s solution test indicate

Answer 18

Negative for starch

Question 19

What color is a negative sudan’s test

Answer 19

Dark red

Question 20

What color is a positive sudan’s test

Answer 20

2 layers of light red and red

Question 21

What color is a positive Biuret’s test

Answer 21

Purple

Question 22

What color is a negative Biuret’s test

Answer 22

Blue

Question 23

What color is a positive Ninhydrin’s test

Answer 23

Purple

Question 24

What color is a negative Ninhydrin’s test

Answer 24

Blue

Question 25

What color is positive for proline Ninhydrin's test

Answer 25

Yellow

Question 26

What color is a negative Benedict's test

Answer 26

Blue

Question 27

What colors are the positive Benedict's test and their percentages

Answer 27

Teal (0-0.5%), Green (0.6-1%), light green (1.1-1.5%), Yellow (1.6-2.5%), orange (2.6-3.5%), red (3.6-4%), brown (>4%)

Question 28

What is the difference between ketones and aldehydes

Answer 28

Aldehyde (carbonyl group at end) is easily oxidized, ketone (carbonyl group in carbon chain) have no particular H atom, resistant to oxidation

Question 29

What does no change in colorless solution on Tollens silver mirror test indicate

Answer 29

Presence of ketone, no aldehyde

Question 30

What does the production of a grey precipitate of silver indicate on Tollens silver mirror test

Answer 30

Presence of aldehyde

Question 31

What result indicates ketone presence/no aldehyde for tollens silver mirror test

Answer 31

No change in colorless solution

Question 32

What result indicates aldehyde presence for tollens silver mirror test

Answer 32

Grey precipitate in silver solution

Question 33

What does no change in blue solution indicate for Fehling's test

Answer 33

Ketone presence, no aldehyde

Question 34

What does dark red precipitate of red copper I oxide on fehling's test indicate

Answer 34

Presence of aldehyde

Question 35

What precipitate is produced in the presence of aldehyde for Fehling's test

Answer 35

Dark red of copper I oxide

Question 36

What result indicates aldehyde presencefor fehlings

Answer 36

Dark red precipitate of copper I oxide

Question 37

What result indicates ketone/no aldehyde presence

Answer 37

No change in blue solution

Question 38

What test is used to test for presence of nucleic acids

Answer 38

Diphenylamine test

Question 39

What does blue on diphenylamine test indicate

Answer 39

DNA presence

Question 40

What does green on diphenylamine test indicate

Answer 40

RNA presence

Question 41

What does colorless on diphenylamine test indicate

Answer 41

Negative for nucleic acids

Question 42

What result indicates DNA presence on diphenylamine test

Answer 42

blue

Question 43

What result indicates RNA presence on diphenylamine test

Answer 43

green

Question 44

What result indicates no nucleic acids on diphenylamine test

Answer 44

Colorless

Question 45

What does the diphenylamine test indicate

Answer 45

Presence of nucleic acids