Carbohydrate Science - Chemical Structure, Composition of Carbs
Including Monosaccharides, Disaccharides, Oligosaccharides, Polysaccharides

Carbs in Food
Glycemic Index GI of Carbs
Glycemic Load of Carbs
GI Diet - Low GI Diet

Information About Carbs - Synthesis of Carbohydrates - Carb Benefits

A Bit of Carb Science

Chemical Composition of Carbohydrate

A carbohydrate is any member of a widespread class of natural organic substances that includes sugars, starch and cellulose. The chemical composition of carbohydrates - as analysed in the nineteenth century - is a combination of carbon (C), hydrogen (H) and water (H2O). Many carbs have the general chemical formula Cx(H2O)x, but the class is too large to fit into a simple chemical formula. Carbohydrates are often isomers - meaning, they have the same atomic composition but different structures. Fructose, galactose and glucose are isomers with the chemical formula C6H12O6. There are many classification schemes for carbohydrates. The most common one separates them into 4 major groups: monosaccharides, disaccharides, oligosaccharides and polysaccharides.

Types of Carbohydrates

Molecules of monosaccharides (simple sugars) usually contain 5-6 carbon atoms. Three most common monosaccharide carbohydrates include (a) glucose (also called dextrose, grape sugar or corn sugar; (b) fructose (fruit sugar); and galactose. Glucose is a constituent of the two most widespread disaccharides, sucrose and lactose, and is the sole structural constituent of the polysaccharides cellulose, starch and glycogen. Galactose is a common constiuent of oligosaccharides and polysaccharides (eg. agar, carrageenan), and also is found in carbohydrate-containing lipids called glycolipids located in brain and nerve tissue.

Disaccharides are composed of 2 simple sugar molecules, hence they are sometimes referred to as "double sugars". For example, the disaccharide sucrose contains one molecule of glucose and one molecule of fructose. Other disaccharide carbs include lactose (milk sugar), mannose, and maltose.

Oligosaccharides - carbohydrates with 3-6 monosaccharide units - are rarer. Many oligosaccharides are prepared by breaking down polysaccharide complex carbs. Most naturally occurring oligosaccharides are found in plants. For example, raffinose is a trisaccharide consisting of melibiose (galactose and glucose) and fructose. By comparison, maltotriose, a trisaccharide of glucose, occurs both in plants and in the bloodstream of certain arthropods.

Polysaccharides (eg. cellulose, starch, glycogen) are much larger molecules which comprise up to 10,000 monosaccharides. Most of the stored carbohydrates in nature occur in the form of polysaccharides.

For example, glycogen - the stored carbohydrate found in the muscles and liver of humans and many animals - consists of a complex chain of glucose molecules. The two most well known polysaccharides are cellulose and starch. Cellulose - the basic structural material in plants - contains over 3,000 glucose molecules.

We encounter cellulose in the form of insoluble dietary fiber. Starch refers to a class of plant-based polysaccharides made up of units of glucose. Starches typically comprise a combination of two substances: amylose and amylopectin. We metabolize starch in our digestive system in stages.

First, digestive enzymes called amylases convert the starch into maltose. As the maltose is absorbed through the walls of the intestine it is hydrolyzed to glucose and distributed to cells and muscles for energy or stored as glycogen or fat.

Carbohydrates Definition
Carbohydrates Information
Complex Carbs Guide
Simple Carbs Guide
Starch/Starchy Carbohydrates
Sugars Carbohydrates
Carb Counting Guide
Facts About Carbohydrates
Diabetes, Carbs and Diet

Fiber in Diet
Dietary Fiber
Types of Fiber
Best Sources of Fiber
Benefits of Fiber
Daily Fiber Needs

Nutrition & Carbohydrate
Nutrition in Carbs
Minerals in Carbohydrates
Vitamins in Carbohydrates
Phytochemicals in Carbs

Carbs and Glycemic Index
Digestion of Carbs
Blood Glucose Levels
Glucose into Energy
What is Glycogen?
How is GI Measured?
What Affects Glycemic Value?
Glycemic Index Food Chart
Glycemic Index Food Pyramid
Glycemic Value of a Meal
GI Values in Carbohydrates
GI Value For Beans
GI Value For Bread
GI Value For Cereal
GI Value For Dairy Food
GI Value For Drinks
GI Value For Fruit
GI Value For Meat/Fish
GI Value For Nuts
GI Value For Snacks
GI Value For Starchy Carbs
GI Value For Sugar
GI Value For Vegetables
GI Value For Whole Grains

Carbohydrate in Foods
Atkins Diet Foods
Energy Bars
Flour/Baking Foods
Ice Cream
Milk, Cream,Yogurt

Carbs in Food cont/
Soy Food
Zone Diet Foods

Diet Recipes
GI Diet Recipes
Low Carb Recipes

Carb-Controlled Diets
Atkins Diet
South Beach Diet
Zone Diet
Low Carb Dieting
Benefits of Low Carb Diets
Low Carb Diets Health Risks
Ketosis - High Ketones in Blood
Gluconeogenesis Guide
Free Low Carb Diet Advice
Low Carb Weight Loss Diet

Diabetes, Insulin, Obesity
Diabetes Information
Hyperglycemia - High Blood Glucose
Hypoglycemia - Low Blood Glucose
Obesity Information
Diabesity, Diabetes and Obesity
Insulin Information
Insulin and Obesity
Types of Insulin
Hyperinsulimia - High Insulin Levels
Insulin Resistance Syndrome provides general information about different types of carbohydrate, like monosaccharides, disaccharides, oligosaccharides, polysaccharides, as well as nutritional value of carbohydrates, carb-content of foods, plus details of GI values of all food groups, plus advice about diabetes, impaired glucose tolerance and insulin resistance. But no information is intended as a substitute for medical advice. Copyright 2003-2021.