Question

part 1: multiple choice

1. keratin is a protein found in hair, nails, and feathers of animals. proteins are biomolecules made primarily out of:

a. monosaccharides
b. amino acids
c. glycerol and fatty acids
d. nucleotides
6.1

1. milk contains a high concentration of the carbohydrate lactose. what is the basic building block of lactose?

a. two monosaccharides joined together
b.

Explanation:

Question 1

To solve this, we analyze each option:

• Option A: Monosaccharides are the building blocks of carbohydrates, not proteins. So A is incorrect.
• Option B: Proteins are polymers made by linking amino acids through peptide bonds. Keratin is a protein, so it is made of amino acids. This is correct.
• Option C: Glycerol and fatty acids are the components of lipids (fats), not proteins. So C is incorrect.
• Option D: Nucleotides are the building blocks of nucleic acids (like DNA and RNA), not proteins. So D is incorrect.

Lactose is a disaccharide. Disaccharides are formed by the joining of two monosaccharides (monomers of carbohydrates) through a glycosidic bond.

• Option A: This matches the definition of a disaccharide (lactose is a disaccharide made of glucose and galactose, two monosaccharides).
• Other options (not fully visible but from context): A chain of amino acids is a protein, so options related to amino acids are for proteins, not carbohydrates like lactose. So the correct description of lactose's building block is two monosaccharides joined together.

Answer:

B. Amino Acids

Question 2