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

   Every cell membrane is built on a double layer of one kind of molecule. Which kind, Bo?

   • Starch grains
   • Nucleic acids
   • Carbohydrates
   • Lipids
3. 3.

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

   • Proteins
   • Lipids
   • Starch
   • Nucleic acids
4. 4.

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

   • A nucleic acid that holds genes
   • A lipid that forms membranes
   • A carbohydrate stored for energy
   • A protein stored for growth
5. 5.

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

   • Glucose units
   • Glycerol and fatty acids
   • Amino acids
   • Nucleotides
6. 6.

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

   • Apple juice
   • Soy
   • Olive oil
   • Potatoes
7. 7.

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

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

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

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

   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
   • Fiber
   • Protein
10. 10.

    Seeds from a purple-flowered pea plant grow into plants with purple flowers. Which molecule carries the flower-color instructions, Zee?

    • A protein from the petals
    • Starch in the seed
    • Water in the seed
    • DNA