Chemical Digestion of Carbohydrates: Definition & Process

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Protein Digestion and Absorption Process

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 0:05 Digestion
  • 0:58 Monosaccharides
  • 1:49 Disaccharides and…
  • 3:05 Hydrolysis
  • 4:15 Lesson Summary
Save Save Save

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Speed Speed

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: 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 are an important energy source, but must be broken down to be absorbed out of the digestive tract. In this lesson, you will learn how disaccharides and polysaccharides are broken down to monosaccharides through a process called hydrolysis.


The calories that you consume during the day basically consist of a combination of three main nutrients, called carbohydrates, proteins and fats. When you sit down to a meal, you probably do not give much thought to what happens to these nutrients as they make their way through your digestive tract. But when we take a closer look, we see that each of these nutrients is made up of long chains of subunits that must be chemically broken down by enzymes.

Nutrients are made up of long chains of subunits that must be broken down by enzymes

These nutrients must be broken down so they are small enough to be absorbed out of your digestive tract, otherwise they would pass right through you, and you would suffer from malnutrition. This lesson will focus on carbohydrates. Carbohydrates are organic compounds, including sugars and starches, that serve as a major energy source for your body. In this lesson, you will learn how the carbohydrates that you eat are broken down in your digestive tract.


The basic building blocks of any carbohydrate, whether it is bread, a baked potato or a plate of pasta, are called monosaccharides. Monosaccharides are defined as simple sugars because they are in their simplest form and cannot be broken down more than they already are. In fact, their name is very descriptive. We see that the prefix 'mono' means one, and the suffix 'saccharide' means sugar. So, a monosaccharide is literally 'one sugar,' standing by itself, with no other units attached to it.

Monosaccharides are the basic building blocks of carbohydrates

There are three common monosaccharides in your diet. They are called glucose, fructose and galactose. Of these three, glucose is the most important, and when we talk about blood sugar levels, we are referring to glucose. Glucose is also a major energy source for your body cells.

Disaccharides and Polysaccharides

When you join a couple of monosaccharides together you form a disaccharide. The prefix 'di' means two, and disaccharides are defined as a class of sugars that are composed of two monosaccharides, basically a 'double sugar.' There are three common disaccharides in your diet, and we call them sucrose, lactose and maltose.

There is one more type of carbohydrate that your digestive system is able to digest and break down into a monosaccharide, and that is starch. Starch is a polysaccharide. The prefix 'poly' means many, and polysaccharides are defined as a class of sugars that are composed of many monosaccharides.

There is another type of polysaccharide that you eat called cellulose. Cellulose is found in foods, such as fruits, vegetables and grains, but your body does not have the enzymes that it needs to break down cellulose. Therefore, we do not get nutrients from cellulose, but these foods do provide us with fiber. Fiber cannot be digested but helps the body move food through the digestive tract. Fiber is almost like a scrub brush that moves through your intestine and keeps food remnants moving along their path.

Cellulose provides us with fiber, which cannot be digested but helps food move through the digestive tract

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account