1. Carbohydrates Sources of Carbohydrates Digestion and Absorption
Simple Sugars
Complex Carbohydrates
Dietary Fiber
Digestion and Absorption
Functions
Blood glucose regulation
Dietary sweeteners
Dietary Recommendations

2. What are Carbohydrates?

4. Types of Carbohydrates
Simple Carbohydrates
monosaccharides
disaccharides
Complex Carbohydrates
oligosaccharides
polysaccharides
glycogen
starches
fibers

5. Carbohydrate and sugar structure
Carbohydrates or saccharides are essential components of living organisms.
(C•H2O)n Where n=3 or greater.
A single saccharide is called a monosaccharide.
Oligosaccharide is a few linked monosaccharides and are at time associated with proteins (glycoproteins) or lipids (glycolipids)
Polysaccharides consist of many monosaccharides i.e. cellulose or glycogen

6. Monosaccharides: Single Sugars
Glucose
carbohydrate form used by the body, referred to as “blood sugar”
basic sub-unit of other larger carbohydrate molecules
found in fruits, vegetables, honey

7. Monosaccharides: Single Sugars
Fructose
sweetest of the sugars
occurs naturally in fruits & honey, “fruit sugar”
combines with glucose to form sucrose
Galactose
combines with glucose to form lactose, “milk sugar”

8. Monosaccharides (D-aldoses)

9. The Fischer convention, the basis for the D- configuration in sugars comes from D-glyceraldhyde’s configuration around its asymmetric carbon.
Epimers differ in configuration around one carbon atom i.e. D-glucose and D-mannose but D-glactose and D-glucose are not epimers because they very around two carbon atoms. There are 2n-2 stereoisomers

10. Carbohydrates are classified as to the nature of the carbonyl group : ketone = ketose aldehyde = aldose
Triose
Tetrose
Pentose
Hexose
2(n-3) stereoisomers of ketoses

12. Disaccharides Sucrose (“table sugar”) Lactose (“milk sugar”)
glucose + fructose
Lactose (“milk sugar”)
glucose + galactose
Maltose (“malt sugar”)
glucose + glucose

14. Joining and Cleaving Sugar Molecules

15. Complex Carbohydrates
Oligosaccharides
short carbohydrate chains of monosaccharides
found in legumes and human milk
Examples:
raffinose
stachyose
cannot be broken down by human enzymes, though can be digested by colonic bacteria

16. Complex Carbohydrates
Polysaccharides
long carbohydrate chains of monosaccharides linked by glycosidic bonds
alpha (a) bonds (starch)
beta (b) bonds (found in fiber)

17. Complex Carbohydrates
amylose
Starch
plant storage form of carbohydrate
long branched or unbranched chains of glucose
amylose
amylopectin
amylopectin

18. Complex Carbohydrates
Glycogen
highly branched chains of glucose units
animal storage form of carbohydrate
found in LIVER and MUSCLE
Humans store ~ 100g in liver; ~ 400g in muscle
negligible source of carbohydrate in the diet (meat)