Carbohydrates, lipids, proteins and nucleic acids

Grade 7 Science Worksheet

Circle the best answer.

1. 1.

   Cellulose gives a plant cell wall its strength. Which kind of molecule is cellulose, Ari?

   • A carbohydrate
   • A nucleic acid
   • A lipid
   • A protein
2. 2.

   Ribosomes are tiny cell parts that join amino acids together. Which molecule do ribosomes make, Esme?

   • Lipids
   • Starch
   • Nucleic acids
   • Proteins
3. 3.

   A potato plant stores extra sugar in its potatoes as starch. Which choice names starch and its job, Jun?

   • A carbohydrate stored for energy
   • A lipid that forms membranes
   • A nucleic acid that holds genes
   • A protein stored for growth
4. 4.

   Sunflower oil is liquid at room temperature. Which building blocks make up its molecules, Kira?

   • Glucose units
   • Glycerol and fatty acids
   • Amino acids
   • Nucleotides
5. 5.

   Luz wants a plant food that is a good source of protein. Which one fits?

   • Olive oil
   • Potatoes
   • Soy
   • Apple juice
6. 6.

   Many amino acids are joined in one long chain, like beads on yarn. What does the chain make, Milo?

   • A nucleic acid
   • A lipid
   • A carbohydrate
   • A protein
7. 7.

   Which of these is not built as a long chain of repeating blocks, Noah?

   • A fat, made of glycerol and fatty acids
   • DNA, made of nucleotides
   • Starch, made of glucose units
   • A protein, made of amino acids
8. 8.

   Each nucleotide holds a sugar, a phosphate and a base. What does a long chain of nucleotides make, Pia?

   • Starch
   • DNA, a nucleic acid
   • A protein
   • A fat
9. 9.

   Partway through a long bike ride, Ren's body starts drawing energy from fat as well. Which family of molecules is fat?

   • Fiber
   • Proteins acting as enzymes
   • Nucleic acids
   • Lipids
10. 10.

    MedlinePlus says one part of food helps the body repair cells and make new ones as children grow. Which one, Tala?

    • Table sugar
    • Plant oils
    • Protein
    • Fiber