1. Nutrients and Carbohydrates A nutrient is any substance that has a useful function when consumed and absorbed into cells.

2. The 3 macronutrients are: 1.Carbohydrates 2.Lipids 3.Proteins The 3 micronutrients 1.vitamins 2.minerals 3.water

3. Carbohydrates Function:Carbohydrate molecules are the main energy source for an organism. Food Sources: pasta, rice, sugars, potatoes Chemical Structure of glucose is C 6 H 12 O 6 - hydrogen: carbon: oxygen in the ratio 1:2:1 There are two main types of carbohydrates, sugars and starches. At least 40% of a healthy diet should be complex carbohydrates or starches and simple carbohydrates like sugar should be avoided.

4. Carbohydrates - Monosaccharides Sugars or simple carbohydrates taste sweet. The most important is the monosaccharide glucose as well as fructose and galactose. Sugar names end in “ose” The basic chemical structure is a ring of 6 carbons shown as:

5. LE 5-4 Linear and ring forms Abbreviated ring structure Glucose dissolved in water is found almost always in a ring form, but dry glucose can have a linear structure.  Glucose  and  glucose ring structures  Glucose

6. Carbohydrates - Disaccharides Joining two monosaccharides forms a disaccharide. Still taste sweet like sucrose and maltose. The basic chemical structure is two 6 carbon rings joined together in a condensation reaction. The bond between 2 monosaccharides is a glycosidic bond.

7. LE 5-5 Glucose Maltose Fructose Sucrose Glucose Dehydration reaction in the synthesis of maltose Dehydration reaction in the synthesis of sucrose 1–4 glycosidic linkage 1–2 glycosidic linkage Remember: A glycosidic linkage is a specific type of ether linkage.

8. LE 5-8 Cellulose molecules Cellulose microfibrils in a plant cell wall Cell walls Microfibril Plant cells 0.5 µm  Glucose monomer

9. Carbohydrates - Polysaccharides Two important polysaccharides are starch and cellulose. Starches taste dry not sweet. Starches are formed by joining many monosaccharides together to form a polysaccharide.

10. LE 5-7b Starch: 1–4 linkage of  glucose monomers. There are two types of glycosidic bonds, alpha or beta bonds. In an alpha glycosidic bond the –OH group on the second carbon is on the opposite side of the ring than the carbon 6 –CH2OH group. This is starch.

11. LE 5-7c Cellulose: 1–4 linkage of  glucose monomers. In cellulose or plant fibre, every second glucose is flipped over and a beta glycosidic bond is formed.