Chapter 4 Biological Molecules (Y10 Bio)

An unknown food sample is analyzed and found to consist solely of carbon, hydrogen, and oxygen. Which two types of macromolecules could this sample potentially contain?

• Carbohydrates and proteins

• Proteins and fats

• Carbohydrates and fats

• Nucleic acids and proteins

A scientist analyzes a compound that contains nitrogen in addition to carbon, hydrogen, and oxygen. Which macromolecule is this compound most likely part of?

• Carbohydrates

• Fats

• Proteins

• Vitamins

Which statement correctly compares the elemental compositions of carbohydrates, fats, and proteins?

• Carbohydrates and fats consist only of carbon, hydrogen, and oxygen, while proteins also include nitrogen.

• Carbohydrates and proteins consist only of carbon, hydrogen, and oxygen, while fats include nitrogen.

• All three macromolecules consist solely of carbon, hydrogen, and oxygen.

• Proteins contain only carbon, hydrogen, and oxygen, while carbohydrates and fats include nitrogen.

Large molecules are formed from smaller units. Which pairing is correct?

• Starch – amino acids

• Protein – fatty acids

• Fats – fatty acids and glycerol

• Cellulose – nucleotides

Starch, glycogen, and cellulose are synthesized from which simple molecule?

• Amino acids

• Glucose

• Fatty acids

• Nucleotides

Proteins are synthesized from:

• Fatty acids

• Amino acids

• Glucose

• Glycerol

Fats and oils are formed from which of the following?

• Glucose and amino acids

• Amino acids and glycerol

• Fatty acids and glycerol

• Fatty acids and glucose

When iodine solution is added to a sample, a deep blue-black color indicates the presence of:

• Proteins

• Fats

• Starch

• Reducing sugars

A Benedict’s solution test that changes from blue to a brick-red precipitate indicates:

• A high concentration of reducing sugars

• The presence of fats

• The absence of amino acids

• The presence of proteins

The Biuret test produces a violet color when:

• Fats are present

• Proteins are present

• Carbohydrates are present

• Vitamin C is present