The structure and types of carbohydrates in our food
Choose two to discuss.
Discuss the structure and types of carbohydrates in our food. Be sure to address the following: sources, refined vs. unrefined, whole grains vs. enriched grains, simple vs. complex carbohydrates, soluble vs. insoluble fiber. (USLO 4.1) Outline the steps involved in the digestion and absorption of carbohydrates. (USLO 4.2) Discuss the various functions of carbohydrates within the body. (USLO 4.3) Pick out 3 of the following conditions and describe the role of carbohydrate intake (USLO 4.4): Metabolic Syndrome Type 1 Diabetes Type 2 Diabetes Gestational Diabetes Hypoglycemia Heart Disease Dental caries Bowel health Hemorrhoids Diverticulitis Discuss the RDA values for carbohydrates for you and your immediate family members. How did you do in meeting those RDA values based on your nutrient intake report? Discuss ways in which you can improve. (USLO 4.5)
Refined Grains: These are grains that have been processed to remove the bran and the germ, leaving only the starchy endosperm.
Example: White flour, white rice, white bread.4
Nutritional Value: This process removes most of the fiber and many vitamins and minerals.
Enriched Grains: These are refined grain products where a few specific B vitamins (thiamin, riboflavin, niacin, folic acid) and iron have been added back after processing.5
Note: The fiber and other nutrients (like magnesium and B6) are not added back, making enriched grains nutritionally inferior to whole grains.
Soluble vs. Insoluble Fiber
Fiber is a complex carbohydrate that the human body cannot digest.6 It is crucial for health and is categorized by its behavior in water:
Type of Fiber
Behavior in Water
Food Sources
Role in the Body
Soluble Fiber
Dissolves in water to form a gel-like substance.
Oats, barley, legumes, citrus fruits, apples.
Helps lower blood cholesterol and blood glucose levels.
Insoluble Fiber
Does not dissolve in water (remains intact).
Whole grains (bran), vegetables (skins/seeds).
Increases stool bulk and helps prevent constipation; promotes bowel health.
Digestion and Absorption of Carbohydrates
Carbohydrate digestion begins in the mouth and continues through the small intestine, breaking down complex starches into single sugar units (monosaccharides) for absorption.7
1. The Mouth
Mechanical Digestion: Chewing breaks food into smaller pieces.8
Chemical Digestion: The salivary enzyme amylase begins to break down long starch chains into shorter polysaccharides and the disaccharide maltose.9
2. The Stomach
Carbohydrate digestion largely halts here.
Salivary amylase is inactivated by the stomach's strong acid (10$\text{HCl}$).11 No major carbohydrate-digesting enzymes are secreted in the stomach.
3. The Small Intestine (Major Digestion Site)
Pancreatic Amylase: The pancreas releases pancreatic amylase into the small intestine.12 This enzyme continues to break down the remaining starch chains into disaccharides (maltose) and very short sugar chains.
Brush Border Enzymes: Enzymes embedded in the lining of the small intestine (the brush border) complete the breakdown:13
Maltase breaks maltose into 2 molecules of glucose.14
Sucrase breaks sucrose into glucose and fructose.
Lactase breaks lactose into glucose and galactose.15
Sample Answer
Structure and Types of Carbohydrates in Food
Carbohydrates are essential macronutrients composed of carbon, hydrogen, and oxygen, and are classified based on the number of sugar units they contain.
Simple vs. Complex Carbohydrates (Structure)
Type
Structure
Components/Sources
Simple Carbohydrates (Sugars)
1 or 2 sugar units
Monosaccharides: Single sugar units (glucose, fructose, galactose). Found in fruits, honey, and high-fructose corn syrup.
Disaccharides: Two sugar units (sucrose, lactose, maltose). Found in table sugar, milk, and beer.
Complex Carbohydrates (Starch and Fiber)
Many sugar units linked together in chains.
Polysaccharides: Long chains of glucose units. Starch (found in grains, legumes, and root vegetables) and fiber (found in plant cell walls).
Refined vs. Unrefined and Whole vs. Enriched Grains (Sources)
The processing of carbohydrate sources significantly impacts their nutritional value, especially for grains:1
Unrefined/Whole Grains: These are grains (like wheat, oats, or rice) consumed in their entirety, containing the bran (fiber, vitamins, minerals), the germ (essential fatty acids, vitamins), and the endosperm (starch).2
We are here to help
We have crazy offers
It’s quick and easy to place an order. We have an efficient customer service that works 24/7 to assist you.It’s quick and easy to place an order. We have an efficient customer service that works 24/7 to assist you.
We are here and ready to help
Ready to join our block community of business leaders for four days of virtual sessions on driving developer happiness and boosting productivity?