Carbohydrate Digestion and Absorption: Process & End Products

Start Your Free Trial To Continue Watching
As a member, you'll also get unlimited access to over 8,500 lessons in math, English, science, history, and more. Plus, get practice tests, quizzes, and personalized coaching to help you succeed.
Free 5-day trial
It only takes a minute. You can cancel at any time.
Already registered? Login here for access.
Start your free trial to take this quiz
As a premium member, you can take this quiz and also access over 8,500 fun and engaging lessons in math, English, science, history, and more. Get access today with a FREE trial!
Free 5-day trial
It only takes a minute to get started. You can cancel at any time.
Already registered? Login here for access.
  1. 0:07 Carbohydrates
  2. 1:35 Brush Border Enzymes
  3. 2:07 Absorption
  4. 3:04 Lesson Summary
Show Timeline
Taught by

Rebecca Gillaspy

Dr. Gillaspy has taught health science at University of Phoenix and Ashford University and has a degree from Palmer College of Chiropractic.

Carbohydrates that you eat are broken down to monosaccharides by enzymes in your digestive tract. In this lesson you will learn about these digestive enzymes and how monosaccharides are absorbed out of the digestive tract.


Carbohydrates are nutrients that provide your body with energy. But before carbohydrates can fuel your morning run, they must be broken down into their basic units, called monosaccharides, and absorbed out of your digestive tract and into your bloodstream. In this lesson, you will learn about the enzymes that break down carbohydrates and how this important nutrient is absorbed.

Carbohydrate digestion begins in the mouth with salivary amylase
Carbohydrate Digestion Begins in Mouth

We previously learned that digestion of carbohydrates, and in particular starches, begins in the mouth with the action of salivary amylase. This enzyme catalyzes, or speeds along, the hydrolysis of the starch molecule. You may recall that hydrolysis is how nutrients that you eat are broken down, and it involves splitting bonds with water.

Even though carbohydrate digestion begins in your mouth, very few of us chew our food long enough for salivary amylase to have a significant effect on the carbohydrates that we eat. So we swallow the carbohydrate somewhat intact. When you swallow the food mass, some of the salivary amylase travels along with it, and you would think that the enzyme would keep working to break down the carbohydrate. However, the enzyme is inactivated in the stomach because the environment of the stomach is too acidic.

Digestion of the carbohydrate does not resume until the food mass reaches the first part of the small intestine that we call the duodenum. Here the carbohydrate meets pancreatic amylase, which is similar to salivary amylase, and continues the breakdown of the carbohydrate.

Brush Border Enzymes

Brush border enzymes in the small intestine complete the digestion of carbohydrates
Brush Border Enzymes

Any remaining sugars are acted upon by brush border enzymes. Brush border enzymes are special enzymes found on the microvilli of the small intestine that complete digestion. We previously learned that microvilli are tiny, hair-like projections that increase surface area of the small intestine and therefore increase nutrient absorption. Because there are so many microvilli, the epithelial cells appear to be fuzzy, like the bristles of a paint brush, leading some anatomists to refer to them as the brush border, hence the name.

Unlock Content Over 8,500 lessons in all major subjects

Get FREE access for 5 days,
just create an account.

Start a FREE trial

No obligation, cancel anytime.

Want to learn more?

Select a subject to preview related courses:

People are saying…

"This just saved me about $2,000 and 1 year of my life." — Student

"I learned in 20 minutes what it took 3 months to learn in class." — Student

See more testimonials

Did you like this?
Yes No

Thanks for your feedback!

What didn't you like?

What didn't you like?

Next Video
Create your Account

Sign up now for your account. Get unlimited access to 8,500 lessons in math, English, science, history, and more.

Meet Our Instructors

Meet all 53 of our instructors