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

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

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

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

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

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

   • Potatoes
   • Soy
   • Olive oil
   • Apple juice
5. 5.

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

   • A lipid
   • A protein
   • A carbohydrate
   • A nucleic acid
6. 6.

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

   • DNA, made of nucleotides
   • A fat, made of glycerol and fatty acids
   • A protein, made of amino acids
   • Starch, made of glucose units
7. 7.

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

   • DNA, a nucleic acid
   • A fat
   • Starch
   • A protein
8. 8.

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

   • Proteins acting as enzymes
   • Lipids
   • Fiber
   • Nucleic acids
9. 9.

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

   • Plant oils
   • Table sugar
   • 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?

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