ATP: the cell's energy carrier

Grade 9 Science Worksheet - Building Confidence

Circle the best answer.

1. Read this first

   Use this

   Flow diagram (model, not to scale), drawn inside the cell. Inputs in boxes on the left. Outputs in boxes on the right.

2. 1.

   Ari reads a diagram of ATP being broken down. Box A holds adenosine with two phosphate groups. What is A?

   • ADP, with two phosphate groups
   • AMP, with one phosphate group
   • ADP, with three phosphate groups
   • ATP, with three phosphate groups
3. 2.

   Esme reads a diagram of ATP being rebuilt in a chloroplast, with light shining on it. What does wavy arrow C show?

   • Energy that ATP gives off as it is rebuilt
   • Energy from light that is used to rebuild ATP
   • Energy that ADP and Pi make by themselves
   • Energy released when the third phosphate joins

4. Use this

   Flow diagram (model, not to scale), drawn inside the cell. Inputs in boxes on the left: ATP: adenosine joined to a row of 3 phosphate circles. No output boxes are drawn. No wavy arrow label is drawn.

5. 3.

   Jun counts the circles in the drawing of ATP. Each circle is a phosphate group. How many phosphate groups does ATP have?

   • 1 phosphate group
   • 4 phosphate groups
   • 3 phosphate groups
   • 2 phosphate groups

6. Use this

   Flow diagram (model, not to scale), drawn inside the cell. Inputs in boxes on the left: ATP: adenosine joined to a row of 3 phosphate circles. Outputs in boxes on the right: ADP: the same drawing with 1 circle fewer; Pi: 1 circle on its own. A wavy arrow points out of the reaction: energy released.

7. 4.

   Kira compares ATP with ADP in the diagram. ADP is drawn with 1 circle fewer than ATP. How many phosphate groups does ADP have?

   • 4 phosphate groups
   • 2 phosphate groups
   • 3 phosphate groups
   • 1 phosphate group

8. Use this

   Flow diagram (model, not to scale), drawn inside the cell. Inputs in boxes on the left: 4 ATP molecules. Outputs in boxes on the right: 4 ADP molecules; the separate Pi groups, one from each ATP. A wavy arrow points out of the reaction: energy released.

9. 5.

   Luz sees 4 ATP molecules broken down, each into one ADP and one Pi. How many Pi groups come off in all?

   • 12 Pi groups
   • 8 Pi groups
   • 1 Pi group
   • 4 Pi groups
10. 6.

    Milo reads that ATP breaks down by hydrolysis. Which phrase tells what hydrolysis means in the diagram?

    • Joining ADP and Pi back into ATP
    • Breaking a bond to create new energy
    • Breaking a molecule apart by adding water
    • Using ATP up so it is gone for good
11. 7.

    Noah reads that ATP is the cell's energy currency, like coins. What does the comparison mean?

    • Cells save ATP for years, like coins in a bank
    • Cells print new ATP at no energy cost
    • Cells spend each ATP once, and it is gone
    • Cells spend ATP's energy on work, then rebuild ATP

12. Use this

    Flow diagram (model, not to scale), drawn inside the cell. No wavy arrow label is drawn. Letter D marks a wavy arrow touching the reaction; its label is blank.

13. 8.

    Ren sees ATP and water turn into ADP and Pi, with a blank wavy arrow D. Which label fits D?

    • Energy out: released for cell work
    • Energy in: added to break ATP down
    • No energy moves: ATP and ADP hold equal energy
    • Energy out: made new as the bond breaks

14. Use this

    Flow diagram (model, not to scale), drawn inside the cell. No wavy arrow label is drawn. Letter E marks a wavy arrow touching the reaction; its label is blank.

15. 9.

    Tala sees ADP and Pi turn into ATP and water, with a blank wavy arrow E. Which label fits E?

    • Energy in: needed to join the third phosphate
    • Energy out: ATP is being broken down here
    • No energy moves: ADP and Pi join with nothing added
    • Energy out: released as the third phosphate joins
16. 10.

    Flow diagram (model, not to scale), drawn inside the cell. No wavy arrow label is drawn. Zee reads where a cell's energy from glucose can go. Which box is the long-term store of energy?

    • Box H, the chain of stored glucose
    • Both, since ATP lasts as long as starch
    • Box G, the ATP that is ready to use
    • Neither, since cells cannot hold energy