Macromolecules Quiz
Questions: 16 · 10 minutes
1. Which structural difference correctly distinguishes DNA from RNA?
DNA contains amino acids, whereas RNA contains fatty acids
DNA contains uracil, whereas RNA contains thymine
DNA contains deoxyribose, whereas RNA contains ribose
DNA contains peptide bonds, whereas RNA contains glycosidic bonds
2. Which macromolecule stores hereditary information in most living organisms?
DNA
Triglyceride
Polysaccharide
Protein
3. A cell needs a flexible boundary that separates its interior from the surrounding fluid. Which macromolecular component primarily forms this boundary?
Phospholipids
DNA
Glycogen
Cellulose
4. Which molecule is a monosaccharide?
Starch
Glucose
Glycogen
Cellulose
5. Two monosaccharides join and release a water molecule. Which process has occurred?
Hydrolysis
Dehydration synthesis
Denaturation
Ionization
6. During digestion, starch from bread is broken into smaller units that can be absorbed. Which final product is expected?
Amino acids
Glycerol
Glucose
Nucleotides
7. Which type of monomer is used to build proteins?
Fatty acids
Monosaccharides
Nucleotides
Amino acids
8. Vegetable oil separates from water when the two are mixed. Which property best explains this observation?
Oil contains many charged phosphate groups
Most of the oil molecules are nonpolar
Oil is made primarily from water-soluble monosaccharides
Oil molecules form peptide bonds with one another
9. An enzyme is exposed to extreme heat and loses the shape of its active site. What most directly explains its reduced activity?
Its amino acids have all changed into sugars
Its peptide bonds have become phosphodiester bonds
Its three-dimensional structure has been disrupted
It has gained a second copy of its genetic code
10. Which statement describes a saturated fatty acid?
It contains at least one carbon-carbon triple bond
It includes a repeating chain of nucleotides
It has several charged phosphate groups along its tail
It has no carbon-carbon double bonds in its hydrocarbon chain
11. A student adds iodine solution to a food sample, and the sample turns blue-black. Which substance is present?
Protein
Reducing sugar
Starch
Lipid
12. After Benedict's reagent is added to a sample and heated, the mixture changes from blue to orange. What does this result indicate?
A phospholipid is present
A protein is present
DNA is present
A reducing sugar is present
13. A muscle cell needs a rapidly available fuel for cellular respiration. Which macromolecule class most directly supplies that fuel?
Nucleic acids
Carbohydrates
Lipids
Proteins
14. A food sample turns violet after Biuret reagent is added. Which conclusion is best supported?
The sample contains starch
The sample contains a reducing sugar
The sample contains only saturated fats
The sample contains peptide bonds
15. A mutation replaces one amino acid in a protein with another. Why might the protein's function change?
The substitution may alter the protein's folding or active site
The protein must become a nucleic acid
Every amino acid substitution removes all peptide bonds
The substitution automatically doubles the protein's size
16. A molecule contains a five-carbon sugar, a phosphate group, and a nitrogenous base. How should it be classified?
A nucleotide
An amino acid
A fatty acid
A monosaccharide