Digestion and how nutrients reach the blood

Grade 9 Science Worksheet - Challenge Me

Circle the best answer.

1. Read this first

   Use this

   Model starch test (model data), 3 rows. Columns: minute, tube 1 amylase, near-neutral, tube 2 amylase with acid, tube 3 water only. 0, 100, 100, 100. 10, 30, 100, 100. 20, 5, 100, 100. Starch left is in relative units. Tube 2 has the acid level of the stomach.

2. 1.

   Ari reads a model card with three tubes. What does it show about amylase in stomach acid?

   • Acid sped up the amylase, since tube 2 lost the most starch
   • Acid stopped the amylase, since tube 2 stays at 100 like tube 3
   • The amylase in tube 1 was used up by minute 20, so its starch fell to 5
   • The three tubes lost starch, with tube 1 losing the most
3. 2.

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

4. Villus route card (real data from OpenStax Anatomy and Physiology 2e)

   product	made from	enters	next stop
   glucose	starch	blood capillary	hepatic portal vein to the liver
   amino acids	protein	blood capillary	hepatic portal vein to the liver
   fatty acids and monoglycerides	fat	lacteal	lymph vessels to the blood

5. 3.

   Esme reads the route card for a lunch of bread, beans and nuts. Which statement matches it?

   • Amino acids enter the lacteal, while fat products enter the blood capillaries
   • Glucose and fat products both enter the lacteal, then travel in lymph vessels
   • Glucose and amino acids enter capillaries; fat products enter the lacteal
   • The three products enter the blood capillaries and go on to the liver
6. 4.

   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
   • Slower, because the oil stays in large globules and lipase reaches less
   • 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
7. 5.

   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
   • 60 units a minute, one third of the folded strip's 180
   • 180 units a minute, three times the folded strip's 60
   • 30 units a minute, the area of the flat strip without the rate
8. 6.

   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 are used up faster
   • 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 turns basic, so the pancreatic enzymes work faster than before

9. 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.

10. 7.

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

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

11. 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

12. 8.

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

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

13. 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.

14. 9.

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

15. 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

16. 10.

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

    • The stomach absorbs most nutrients, after pepsin starts the protein digestion there
    • 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 small intestine takes back water, and the large intestine finishes the digestion