Quiz: Chemical Composition of Cells

Question 1

Plant cell walls are composed of:

Answer 1

cellulose

Question 2

Which reagent indicates for the presence of proteins by turning a solution lavender?

Answer 2

biurets

Question 3

Proteins are chains of _____ bonded together.

Answer 3

amino acids

Question 4

Which of the following should be a negative Benedicts tes?

Answer 4

steroids, starch, collagen, amino acids

Question 5

Which of the following would test positive for Biuret’s regent?

Answer 5

enzymes

Question 6

True or False: Steroids are made from cholesterol which is an amino acid.

Answer 6

False

Question 7

Which of the following is a monomer?

Answer 7

an amino acid and a glucose molecule

Question 8

What must be present to successfully break down fats during digestion?

Answer 8

bile salts

Question 9

The negative control used in the tests for protein was:

Answer 9

starch

Question 10

Which of the following tests is sued to detect the presence of lipids?

Answer 10

brown paper test

Question 11

Starches are polymers composed of?

Answer 11

monosaccharides

Question 12

If you test a sample of potato with Biuret’s reagent, what would you expect the results to be?

Answer 12

negative

Question 13

If several fatty acids, glycerol, and a phosphate group undergo a dehydration reaction, what biomolecule is formed?

Answer 13

fat

Question 14

An unknown liquid sample is tested for chemical composition. You recieve the following results: iodine test=yellow; biuret test=blue; benedict’s test=blue; and paper lipid test=clear. Which of the are present in this sample?

Answer 14

lipid

Question 15

A negative control is a sample that you know will give you a negative result. You are testing for the presence of proteins, simple sugars, starch, and lipids in various foods. What would be the best negative controls for this experiment?

Answer 15

distilled water, because it does not contain any of the molecules you are testing for.