Digestion and how nutrients reach the blood

Grade 9 Science Worksheet - Challenge Me

Circle the best answer.

1. 1.

   The 8.1 and 0.9 were worked out from 9 and 90 percent. Bo reads the water card. Which statement does it support?

   • The small intestine absorbs about 8.1 L of the 9 L, leaving about 0.9 L
   • The small intestine absorbs about 9 L, and the large intestine adds 0.9 L back
   • The small intestine absorbs the full 9 L, so no water reaches the large intestine
   • The small intestine absorbs about 0.9 L, leaving about 8.1 L for the large intestine
2. 2.

   Jun reads about a model tube of oil and lipase with no bile. How does oil digestion compare with a tube that has bile?

   • Faster, because lipase no longer has to share the oil with bile in the tube
   • Faster, because larger globules give lipase more surface area to reach
   • The same, because chewing already finished the digestion of the oil in the mouth
   • Slower, because the oil stays in large globules and lipase reaches less
3. 3.

   Kira reads the model. How much glucose does the flat strip take up in a minute, and how does that compare with the folded strip?

   • 60 units a minute, the same as the folded strip
   • 180 units a minute, three times the folded strip's 60
   • 60 units a minute, one third of the folded strip's 180
   • 30 units a minute, the area of the flat strip without the rate
4. 4.

   Luz reads a model in which pancreatic juice enters the small intestine without its bicarbonate. What happens to the acidic chyme and to the pancreatic enzymes?

   • The chyme stays acidic, so the pancreatic enzymes work more slowly
   • The chyme is unchanged, since enzymes work the same at any level of acidity
   • The chyme stays acidic, so the pancreatic enzymes are used up faster
   • The chyme turns basic, so the pancreatic enzymes work faster than before

5. Read this first

   Use this

   Notebook (model data), 4 rows. Columns: line, what it says. 1, Chewing breaks the bread into smaller pieces. 2, Salivary amylase starts changing starch into maltose. 3, In the stomach, pepsin finishes digesting the starch. 4, In the small intestine, pancreatic amylase continues the starch breakdown.

6. 5.

   Milo reviews a notebook on digesting bread. Exactly one line is wrong. Which line, and why?

   • Line 1, because chewing is chemical digestion
   • Line 4, because amylase was used up in the mouth and cannot work again
   • Line 3, because pepsin digests protein, not starch
   • Line 2, because the mouth just chews and starts no digestion

7. Notebook (model data)

   line	what it says
   1	Most absorption happens in the small intestine
   2	Each villus holds capillaries and a lacteal
   3	Sugars and amino acids enter the lacteal
   4	The large intestine takes back water

8. 6.

   Noah reviews a notebook on absorption. Exactly one line is wrong. Which line, and why?

   • Line 2, because a lacteal is found in the stomach wall
   • Line 4, because the large intestine absorbs most nutrients, not water
   • Line 3, because sugars and amino acids enter blood capillaries
   • Line 1, because the stomach absorbs most nutrients

9. Use this

   Notebook (model data), 4 rows. Columns: line, what it says. 1, Amylase breaks starch into sugars. 2, Pepsin breaks protein into smaller peptides. 3, After it breaks one starch chain, an amylase molecule is used up. 4, Lipase breaks fats into fatty acids and monoglycerides.

10. 7.

    Pia reviews a notebook on enzymes. Exactly one line is wrong. Which line, and why?

    • Line 2, because pepsin, like amylase, also digests starch in bread
    • Line 3, because an enzyme comes out unchanged and works again
    • Line 1, because amylase breaks down the protein in beans and eggs
    • Line 4, because lipase makes amino acids from the protein in food

11. Organ card (real data from OpenStax)

    organ	main job
    Stomach	churns food and starts protein digestion with pepsin
    Small intestine	finishes digestion and absorbs nearly all nutrients through villi
    Large intestine	takes back water and salts and has no villi

12. 8.

    Ren compares three organs on a card. Which statement matches it?

    • The small intestine takes back water, and the large intestine finishes the digestion
    • The small intestine absorbs nearly all nutrients; the large one takes back water
    • The large intestine absorbs most nutrients, through the many villi in its long wall
    • The stomach absorbs most nutrients, after pepsin starts the protein digestion there

13. Enzyme card (real data from OpenStax)

    enzyme	made by	works in	breaks starch into
    Salivary amylase	salivary glands	mouth	maltose
    Pancreatic amylase	pancreas	small intestine	maltose

14. 9.

    Tala compares two enzymes on a card. Which statement is correct?

    • Salivary amylase digests starch, protein and fat, while pancreatic amylase digests starch
    • Both make maltose from starch; one works in the mouth, one in the small intestine
    • Salivary amylase works in the small intestine, and pancreatic amylase in the mouth
    • Pancreatic amylase is the same amylase carried down from the mouth

15. Absorption card (real data from OpenStax Anatomy and Physiology 2e)

    nutrient	share absorbed in the small intestine (percent)
    protein	95 to 98
    fats	about 95
    water	about 90

16. 10.

    Zee reads the absorption card. Which statement fits it?

    • The large intestine takes in about 95 percent of the fats and 90 percent of the water
    • The small intestine takes in about 95 percent of the water and 90 percent of the fats
    • The small intestine takes in about 90 percent of water and 95 percent of fats
    • The stomach takes in about 95 to 98 percent of the protein