Active transport: pumps and vesicles

Grade 9 Science Worksheet

Circle the best answer.

1. Read this first

   Use this

   Membrane drawing (model, not to scale). A bilayer: a top row of round heads, tails meeting in the middle, and a bottom row of round heads, with watery fluid outside the cell above and watery fluid inside the cell below. Letter P points to a sodium-potassium pump across the bilayer, with 1 ATP label beside it. A note says the pump runs 4 cycles and uses 1 ATP in each cycle.

2. 1.

   Ari’s drawing shows a sodium-potassium pump that runs 4 cycles and uses 1 ATP in each cycle. How many ATP are used, and how many ions move?

   • 4 ATP used, 12 sodium ions out, 8 potassium ions in
   • 4 ATP used, 8 sodium ions out, 12 potassium ions in
   • 4 ATP used, 12 sodium ions out, 12 potassium ions in
   • 12 ATP used, 12 sodium ions out, 8 potassium ions in
3. 2.

   A sodium-potassium pump in Bo’s drawing has moved 12 potassium ions into the cell, using 1 ATP per cycle. How many sodium ions has it moved out, and how many ATP has it used?

   • 8 sodium ions out, using 4 ATP
   • 18 sodium ions out, using 6 ATP
   • 18 sodium ions out, using 12 ATP
   • 12 sodium ions out, using 6 ATP

4. Use the table

   Lab card (model data), not to scale. Counts before the sodium-potassium pump P, which sits in a bilayer, runs.

   Ion	Outside the cell	Inside the cell
   sodium ions	40	15
   potassium ions	10	30

   A note says pump P then runs 3 cycles. The card is read about only: a teacher counted the ions, and no one handled anything.

5. 3.

   Esme reads the counts before a pump runs 3 cycles. What are the counts after the 3 cycles?

   • Sodium: 46 outside, 9 inside; potassium: 1 outside, 39 inside
   • Sodium: 49 outside, 6 inside; potassium: 4 outside, 36 inside
   • Sodium: 43 outside, 12 inside; potassium: 7 outside, 33 inside
   • Sodium: 31 outside, 24 inside; potassium: 16 outside, 24 inside

6. Use this

   Membrane drawing (model, not to scale). A bilayer: a top row of round heads, tails meeting in the middle, and a bottom row of round heads, with watery fluid outside the cell above and watery fluid inside the cell below. Letter G points to a protein across the bilayer that carries sodium ions and glucose molecules into the cell together; no ATP label is beside G. Outside the cell: 50 sodium ions and 6 glucose molecules. Inside the cell: 10 sodium ions and 30 glucose molecules.

7. 4.

   Kira’s drawing shows protein G moving glucose into a cell that already holds more glucose than the outside. What kind of transport is this?

   • Primary active transport, because proteins that move glucose use ATP directly
   • Secondary active transport, because glucose moves down its gradient
   • Secondary active transport, because the sodium gradient supplies the energy
   • Facilitated diffusion, because a protein carries glucose across

8. Use this

   Membrane drawing (model, not to scale).

9. 5.

   Luz’s drawing shows carrier H moving glucose from outside (30 molecules) to inside (10 molecules), with no ATP label. What kind of transport is this?

   • Secondary active transport, because the carrier changes shape
   • Facilitated diffusion, because glucose moves down its gradient with no ATP
   • Primary active transport, because glucose moves down its gradient
   • Primary active transport, because a carrier protein is used
10. 6.

    Milo’s drawing shows a membrane folding around a large particle and engulfing it into a vesicle. Which process is this?

    • Receptor-mediated endocytosis, which binds one kind of substance
    • Pinocytosis, which takes in a small drop of fluid
    • Exocytosis, which brings a large particle into the cell
    • Phagocytosis, which engulfs a large particle
11. 7.

    Receptor proteins on Noah’s cell membrane bind one kind of substance, and the membrane pinches in around it. Which process is this?

    • Phagocytosis, which engulfs a large particle of any kind
    • Exocytosis, which takes in one specific substance
    • Pinocytosis, which takes in a drop of fluid
    • Receptor-mediated endocytosis, which takes in one specific substance

12. Use this

    Membrane drawing (model, not to scale). A bilayer: a top row of round heads, tails meeting in the middle, and a bottom row of round heads, with watery fluid outside the cell above and watery fluid inside the cell below. A gland cell packaged an enzyme in a secretory vesicle at the Golgi apparatus. Letter V points to the vesicle, which fuses with the bottom row and releases 5 enzyme molecules to the outside of the cell.

13. 8.

    A gland cell in Pia’s drawing has a vesicle from the Golgi apparatus that fuses with the plasma membrane and releases an enzyme outside. Which process is this?

    • Endocytosis, which releases the contents outside
    • Phagocytosis, which engulfs a large particle
    • Exocytosis, which releases the contents outside
    • Pinocytosis, which takes in a drop of fluid

14. Use this

    Membrane drawing (model, not to scale). A bilayer: a top row of round heads, tails meeting in the middle, and a bottom row of round heads, with watery fluid outside the cell above and watery fluid inside the cell below. Letter P points to a sodium-potassium pump that faces the inside of the cell. 3 sodium ions are attached to it, 1 ATP has been split, and a phosphate group is attached to P. Outside the cell: 2 potassium ions.

15. 9.

    Ren’s drawing shows a sodium-potassium pump after ATP has been split. What does the pump do next?

    • It changes shape to face the outside and lets go of the 3 sodium ions
    • It stays facing the inside while the sodium ions slip out
    • It changes shape to face the outside and binds 3 potassium ions
    • It lets go of the 3 sodium ions inside the cell and takes up more

16. Use this

    Membrane drawing (model, not to scale). A bilayer: a top row of round heads, tails meeting in the middle, and a bottom row of round heads, with watery fluid outside the cell above and watery fluid inside the cell below. Letter G points to a protein across the bilayer that carries sodium ions and glucose molecules into the cell together; no ATP label is beside G. Outside the cell: 60 sodium ions and 10 glucose molecules. Inside the cell: 8 sodium ions and 25 glucose molecules.

17. 10.

    Zee’s drawing shows protein G open, with sodium ions and glucose outside. Predict what happens to the glucose molecules at G.

    • They keep moving in, carried by sodium ions moving down their gradient
    • They move in with no energy source, since carriers use no energy
    • They move in, and G uses ATP directly to carry them
    • They stop, since glucose would have to move toward more glucose