Biomolecule Identifying Tests Flashcards
What does the Sudan test look for?
Lipids
What result does dark red on the Sudan test indicate?
Negative for lipids
What a result of two layers of light red and red indicate on the Sudan test?
Positive for lipids
What is the Biuret test used to detect?
Proteins
What does purple on the Biuret test indicate?
Positive for proteins
What does blue on the Biuret test indicate?
Negative for proteins
What is the Bradford protein assay?
Quantitatively determines how much protein is present with Coomassie Brilliant Blue dye
What is the Ninhydrin test used to detect?
Amino acids based on presence of carboxyl groups of proteins peptides
What does purple on the Ninhydrin test indicate?
Positive for amino acids
What does yellow on the Ninhydrin test indicate?
Positive for proline
What does blue on the ninhydrin test indicate?
Negative
What is the Benedict’s test used to detect?
Reducing sugars (all monosaccharides bearing aldehyde groups in open form)
What does blue on the Benedict’s test indicate?
0% reducing sugars
What does Lugol’s iodine solution test indicate
Starch
What color is a positive Lugol’s solution test
Dark blue/black
What does a dark blue/black lugol’s solution test indicate
Positive for starch
What color is a negative Lugol’s solution test
Reddish orange
What does a reddish orange lugol’s solution test indicate
Negative for starch
What color is a negative sudan’s test
Dark red
What color is a positive sudan’s test
2 layers of light red and red
What color is a positive Biuret’s test
Purple
What color is a negative Biuret’s test
Blue
What color is a positive Ninhydrin’s test
Purple
What color is a negative Ninhydrin’s test
Blue
What color is positive for proline Ninhydrin’s test
Yellow
What color is a negative Benedict’s test
Blue
What colors are the positive Benedict’s test and their percentages
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%)
What is the difference between ketones and aldehydes
Aldehyde (carbonyl group at end) is easily oxidized, ketone (carbonyl group in carbon chain) have no particular H atom, resistant to oxidation
What does no change in colorless solution on Tollens silver mirror test indicate
Presence of ketone, no aldehyde
What does the production of a grey precipitate of silver indicate on Tollens silver mirror test
Presence of aldehyde
What result indicates ketone presence/no aldehyde for tollens silver mirror test
No change in colorless solution
What result indicates aldehyde presence for tollens silver mirror test
Grey precipitate in silver solution
What does no change in blue solution indicate for Fehling’s test
Ketone presence, no aldehyde
What does dark red precipitate of red copper I oxide on fehling’s test indicate
Presence of aldehyde
What precipitate is produced in the presence of aldehyde for Fehling’s test
Dark red of copper I oxide
What result indicates aldehyde presencefor fehlings
Dark red precipitate of copper I oxide
What result indicates ketone/no aldehyde presence
No change in blue solution
What test is used to test for presence of nucleic acids
Diphenylamine test
What does blue on diphenylamine test indicate
DNA presence
What does green on diphenylamine test indicate
RNA presence
What does colorless on diphenylamine test indicate
Negative for nucleic acids
What result indicates DNA presence on diphenylamine test
blue
What result indicates RNA presence on diphenylamine test
green
What result indicates no nucleic acids on diphenylamine test
Colorless
What does the diphenylamine test indicate
Presence of nucleic acids
