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?

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

3. Use this

   Flow diagram (model, not to scale), drawn inside the mitochondrion. Inputs in boxes on the left. Outputs in boxes on the right. A wavy arrow points into the reaction.

4. 2.

   Bo reads a diagram of ATP being rebuilt inside a mitochondrion. Box B is one separate phosphate group. What is B called?

   • Ribose, a five-carbon sugar
   • Pi, an inorganic phosphate group
   • ADP, adenosine with two phosphates
   • Adenine, a nitrogenous base

5. 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.

6. 3.

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

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

7. 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.

8. 4.

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

   • 8 Pi groups
   • 12 Pi groups
   • 4 Pi groups
   • 1 Pi group
9. 5.

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

   • Breaking a bond to create new energy
   • Joining ADP and Pi back into ATP
   • Breaking a molecule apart by adding water
   • Using ATP up so it is gone for good
10. 6.

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

    • Cells print new ATP at no energy cost
    • Cells save ATP for years, like coins in a bank
    • Cells spend each ATP once, and it is gone
    • Cells spend ATP's energy on work, then rebuild ATP
11. 7.

    Flow diagram (model, not to scale), drawn inside the mitochondrion. Pia reads a diagram labeled ATP regeneration. What does regeneration mean here?

    • Rebuilding ATP from ADP and Pi, using energy
    • Making ATP from ADP and Pi while energy comes out
    • Breaking ATP into ADP and Pi to release energy
    • Making ATP from ADP and Pi with no energy needed

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

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 out: ATP is being broken down here
    • No energy moves: ADP and Pi join with nothing added
    • Energy in: needed to join the third phosphate
    • 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?

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