Digestion of Carbohydrates

Flashcards covering key concepts in the digestion and absorption of carbohydrates, enzymes involved, and lactose intolerance.

What are the two types of carbohydrates that can be digested by the human digestive system?

Sugars and starches.

What is the name of the chewing process that mechanically breaks carbohydrate foods into smaller pieces?

Mastication.

Which enzyme in saliva initiates the chemical digestion of starch in the mouth?

Salivary amylase (ptyalin).

Roughly what percentage of starches are broken down in the mouth?

About 5%.

Why does carbohydrate digestion temporarily halt in the stomach?

The acidic environment in the stomach inactivates salivary amylase.

Where does carbohydrate digestion resume after leaving the stomach?

In the duodenum (upper part of the small intestine).

Which enzyme released from the pancreas continues starch breakdown in the small intestine?

Pancreatic amylase.

Pancreatic amylase primarily converts starch into which three disaccharides?

Maltose, sucrose, and lactose.

What does the enzyme maltase do?

It breaks maltose into two glucose molecules.

What does the enzyme sucrase do?

It breaks sucrose into glucose and fructose.

What does the enzyme lactase do?

It breaks lactose into glucose and galactose.

What condition results from insufficient lactase production?

Lactose intolerance.

List common symptoms of lactose intolerance.

Diarrhea, bloating, gas, and abdominal cramps.

Which racial and ethnic groups have higher incidences of lactose intolerance?

African Americans, Hispanic Americans, American Indians, and Asian Americans.

Which population typically has the lowest incidence of lactose intolerance?

People of northern European descent.