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9th grade · Science · Unit 7 of 14

Biomolecules & Enzymes

Carbohydrates, lipids, proteins and nucleic acids, and how enzymes speed up reactions.

What your child practices

Practices the four kinds of biomolecules (carbohydrates, lipids, proteins and nucleic acids), their building blocks and jobs in the cell, and how enzymes speed up cellular reactions and are affected by temperature and pH.

Texas Essential Knowledge and Skills (TEKS) teks student expectation: B.5(A); B.11(B) · the structure and function of biomolecules, and the role of enzymes

How we explain it

Children can open this short lesson before they practice.

  1. Four biomolecules: carbohydrates (quick energy), lipids (stored energy, membranes), proteins (work and structure), nucleic acids (genetic information).
  2. Enzymes are proteins that speed up reactions and are not used up.
  3. Each enzyme works best at a certain temperature and pH.

Example: Which biomolecule stores genetic information? DNA and RNA carry the instructions. They are nucleic acids. Answer: nucleic acids

Biomolecules & Enzymes in Texas

In the Texas Essential Knowledge and Skills (TEKS), this is unit 7 of 14 in 9th grade Science, after Photosynthesis & Respiration and before Cell Types, Transport & Specialization.

Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.

Source: Texas Education Agency (TEA)

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    A protein's function depends on its…

    • number of cells
    • weight only
    • color
    • three-dimensional shape

  2. Question 2

    The cell membrane is made mainly of a double layer of…

    • DNA
    • starch
    • phospholipids
    • proteins only

  3. Question 3

    Enzymes are mostly…

    • carbohydrates
    • nucleotides
    • lipids
    • proteins

  4. Question 4

    Plants store energy as…

    • glycogen
    • DNA
    • starch
    • cholesterol

  5. Question 5

    Which biomolecule stores long-term energy and insulates?

    • Nucleic acids
    • Carbohydrates only
    • Lipids
    • Enzymes

  6. Question 6

    Ribosomes build proteins by linking…

    • amino acids
    • nucleotides
    • glucose
    • fatty acids

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