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?

   • The three tubes lost starch, with tube 1 losing the most
   • 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
   • Acid sped up the amylase, since tube 2 lost the most starch
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 the full 9 L, so no water reaches the large intestine
   • 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

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?

   • 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
   • Amino acids enter the lacteal, while fat products enter the blood capillaries
6. 4.

   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
   • 30 units a minute, the area of the flat strip without the rate
   • 60 units a minute, one third of the folded strip's 180
7. 5.

   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 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
   • The chyme stays acidic, so the pancreatic enzymes work more slowly

8. 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.

9. 6.

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

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

10. 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

11. 7.

    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 4, because the large intestine absorbs most nutrients, not water
    • Line 2, because a lacteal is found in the stomach wall
    • Line 1, because the stomach absorbs most nutrients

12. 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.

13. 8.

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

    • Line 4, because lipase makes amino acids from the protein in food
    • 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

14. 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

15. 9.

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

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

16. 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

17. 10.

    Zee reads the absorption card. Which statement fits it?

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