Macromolecule — Science definition
A large molecule; many biological macromolecules are polymers, but not every biological molecule grouped with them is a repeating-unit polymer.
Where it is taught
- Carbon & the Macromolecules of Life — Investigating the Chemistry of Life, Life Science: Biology, Grade 10
Questions using macromolecule
Problem 1
Which macromolecule family stores genetic information?
- Protein
- Lipid
- Carbohydrate
- Nucleic acid
Answer and explanation
Nucleic acid
Nucleic acids — DNA and RNA — store and carry the genetic instructions for building proteins.
Problem 2
Which pairing of macromolecule and monomer is correct?
- Protein — nucleotide
- Nucleic acid — amino acid
- Carbohydrate — monosaccharide
- Lipid — glucose
Answer and explanation
Carbohydrate — monosaccharide
Carbohydrates are built from monosaccharides. Proteins use amino acids, nucleic acids use nucleotides, and lipids are not true polymers of a single repeating monomer.
Problem 3
A nutrition label lists 0 g of fat but the food is high in calories. Explain how that is possible using macromolecule energy densities.
Answer and explanation
Carbohydrate and protein also supply energy, about 17 kJ per gram each. A food with no fat can still be dense in carbohydrate, so its energy content comes from sugars or starch rather than lipids. Energy content depends on how much of each macromolecule is present, not on fat alone.
Response criteria
- State a biologically accurate conclusion.
- Show the data, mechanism, or calculation that supports it.
- Include units, conditions, or limits where relevant.