Bile from the liver

The idea

The small intestine, site of complete digestion of carbohydrates, proteins and fats, receives bile from the liver, which makes the acidic food alkaline for pancreatic enzymes; bile salts emulsify fats into smaller globules.

Oil and water

Oil does not mix well with water. In your food, fats come as large globules.

What do you think helps enzymes to act on large fat globules?

• Breaking them into smaller globules
• Making them larger
• Leaving them alone

In the small intestine

Press Next step to follow the food.

Bile does two jobs

Bile is made by the liver and flows into the small intestine. It does two jobs. It makes the acidic food from the stomach alkaline, so that the enzymes of the pancreas can act. It also contains bile salts, which break the large fat globules into smaller ones, as soap breaks up dirt.

The small intestine, site of complete digestion of carbohydrates, proteins and fats, receives bile from the liver, which makes the acidic food alkaline for pancreatic enzymes; bile salts emulsify fats into smaller globules.

Notes

Bile from the liver makes the acidic food alkaline for the pancreatic enzymes, and bile salts emulsify fats into smaller globules, in the small intestine.

Check yourself

Which organ makes the bile that reaches the small intestine?

Why must the acidic food from the stomach be made alkaline in the small intestine?

What do bile salts do to large fat globules?

The small intestine is the site of complete digestion of ...

• The pancreas. The pancreas secretes pancreatic juice, which contains trypsin and lipase.
• The liver — correct. Yes!
• The stomach. The gastric glands of the stomach release hydrochloric acid, pepsin and mucus.
• So that pepsin can act. Pepsin acts in the acidic medium of the stomach.
• So that salivary amylase can act. Salivary amylase acts on starch in the mouth, where food is mixed with saliva.
• So that the pancreatic enzymes can act — correct. Yes!
• Break them into smaller globules — correct. Yes!
• Turn them into amino acids. Amino acids are the final products of protein digestion; bile salts only break the globules into smaller ones.
• Turn them into starch. Fats are finally converted into fatty acids and glycerol. Starch is a carbohydrate.
• starch only. Digestion of starch begins in the mouth, and the small intestine completes the digestion of carbohydrates, proteins and fats.
• carbohydrates, proteins and fats — correct. Yes!
• proteins only. The small intestine completes the digestion of carbohydrates and fats as well as proteins.