How cell parts work together to make and ship a protein

Grade 9 Science Worksheet

Circle the best answer.

1. 1.

   Cell cutaway (animal cell, model, not to scale). Ari's class studies a gland cell that releases a digestive enzyme, a protein. Letter C, the Golgi apparatus, stops working. What most likely happens to the enzyme?

   • It is held up at the plasma membrane, because the Golgi comes last
   • It still leaves the cell, because each part works alone
   • It is made and folded but not packaged, so it stays in the cell
   • No enzyme is made, because the Golgi apparatus builds the protein

2. Read this first

   Use this

   Cell cutaway (animal cell, model, not to scale). The route has 7 stations, numbered 1 to 7, joined by arrows. Letter A marks the large round body near the middle, with a double wall (station 1). Letter B marks a small gap in the wall of the large round body (station 2). Letter C marks the flat folded sacs studded with tiny dots, joined to the wall of the large round body (station 3). Letter D marks the stack of curved smooth sacs, away from the dotted sacs (station 5).

3. 2.

   Bo studies a cell that releases a protein. Its nuclear pores, letter B, become blocked. What most likely happens at the rough ER, letter C?

   • Protein piles up at the Golgi, because the pore comes after the Golgi
   • The nucleus builds the protein inside and passes it on, so release goes on
   • Little new protein is built, because mRNA cannot reach the ribosomes
   • The Golgi apparatus builds the protein instead, so release goes on
4. 3.

   Cell cutaway (animal cell, model, not to scale). Esme reads that vesicle C can no longer bud from the rough ER, letter B. Where does a new protein most likely pile up?

   • In the Golgi anyway, because a vesicle is a permanent pipe between them
   • In the Golgi anyway, because the Golgi works alone to collect it
   • In the rough ER, because nothing carries it to the Golgi apparatus
   • In the Golgi, because the Golgi builds a new copy of the protein
5. 4.

   Pulse-chase card, read about only: a teacher followed a labeled membrane protein through a cell. Kira reads a card for a membrane protein. At 45 minutes the label is in the plasma membrane. What carried it there?

   • The nucleus, which sent the finished protein straight there
   • A transport vesicle from the rough ER, skipping the Golgi apparatus
   • A permanent pipe running from the rough ER to the membrane
   • A secretory vesicle from the Golgi that fused with the membrane

6. Use the table

   Pulse-chase card, read about only. Share of the label in each place (model data)

   minutes after labeling	rough ER (%)	Golgi apparatus (%)	outside the cell (%)
   5	80	15	5
   20	30	55	15
   40	10	25	65

7. 5.

   Luz reads the card. Which statement about the label is best supported by the table?

   • It moves from outside to the Golgi to the rough ER, because outside is largest at 40 minutes
   • The Golgi built the label, because its share is largest at 20 minutes
   • Each part works alone, because the shares in each row add up to 100
   • It moves from the rough ER to the Golgi to outside, so parts pass it along

8. Parts counted in one slice of each cell (model data)

   cell	rough ER sacs	mitochondria
   P	48	12
   Q	9	85

9. 6.

   Milo reads counts for two cells. One is from a salivary gland and releases a digestive enzyme. The other is a muscle cell. Which pairing do the counts support?

   • P is the gland cell, because mitochondria build the digestive enzyme
   • Cannot tell, because each part works alone, so counts do not follow the job
   • Q is the gland cell, because cells that secrete proteins have many mitochondria
   • P is the gland cell, since secreting cells have abundant rough ER
10. 7.

    Noah reads that cell X is a pancreas cell that makes digestive enzymes, which are proteins. Cell Y makes little protein. Which statement fits the counts?

    • Y has more ribosomes, because cells that make little protein need more
    • X has far more ribosomes, as cells making much protein need them
    • X has more ribosomes and more nuclei to build the extra protein
    • X has more ribosomes, yet the Golgi apparatus is what builds the protein
11. 8.

    Ren asks how the rough ER (A) and the Golgi apparatus (C) work together on a protein that leaves the cell. Which statement is right?

    • The rough ER makes and folds it, then a vesicle hands it to the Golgi
    • A permanent pipe joins the two parts, and the protein slides through it
    • The Golgi builds the protein first, then the rough ER packages it for release
    • Each part works alone: the Golgi builds its own second copy of the protein
12. 9.

    Cell cutaway (plant cell, model, not to scale). Part A makes sugar by photosynthesis. Tala studies a plant cell. Part A makes sugar by photosynthesis. How does part B, the bean-shaped part, use that sugar?

    • B uses the sugar in cellular respiration to provide ATP energy
    • B makes its own sugar, so it does not use the sugar from A
    • B packages the sugar into vesicles, as the Golgi apparatus does
    • B makes the sugar that A uses for photosynthesis

13. Use this

    Cell cutaway (animal cell, model, not to scale). The route has 7 stations, numbered 1 to 7, joined by arrows. Letter A marks the large round body near the middle, with a double wall (station 1). Letter B marks a small gap in the wall of the large round body (station 2). Letter C marks the flat folded sacs studded with tiny dots, joined to the wall of the large round body (station 3).

14. 10.

    Zee asks what the ribosomes on the rough ER (C) need from the nucleus (A) before they can build a protein. What is it?

    • A packaged protein sent over from the Golgi apparatus
    • mRNA, which leaves A through B with the message for the protein
    • Nothing, since the rough ER builds proteins without any help from A
    • The finished protein, which A builds inside and passes out through B