Concept 5.2: Carbohydrates provide fuel and building material

Counting “Carbs” (aka Sugars) Carbohydrates contain carbon, hydrogen, and oxygen in the ratio: 1C : 2H : 1O Basic molecular formula: CH2O. Usually found as carbon skeletons that have a ring shape.

Which of the following is NOT a valid formula for a carbohydrate? Basic molecular formula: CH2O “carbo” (carbon) “hydrate” (water)

Carbohydrates Come in Many Forms Monomer = Monosaccharides Example: Glucose (C6H12O6) Dimer = Disaccharides Example: Sucrose (C12H22O11) Polymer = Polysaccharides Example: Starch

What is the name of this carbohydrate? starch glucose sucrose fructose Note the six carbon atoms in a ring-shaped arrangement. Glucose: C6H12O6

Lactose is a monosaccharide. True False Lactose Lactose is a disaccharide composed of two monosaccharides: glucose & galactose. People who are “lactose intolerant” are unable to metabolize lactose. MILK

Glucose is hydrophilic. True False This is due to its many hydroxyl groups. Recall that the hydroxyl functional group attracts water. Therefore, monosaccharides and disaccharides dissolve readily in water, forming sugary solutions. Starch and cellulose do not dissolve readily, but they do attract water.

Functions of Carbohydrates Short Term Energy Monosaccharides (plants & animals) Example: fructose 2) Long Term Energy Polysaccharides Starch (plants) Glycogen (animals) 3) Structure Cellulose (plant cell walls) Chitin (animal exoskeletons) potatoes turkey cellulose chitin

Examples of Polysaccharides

Which of the following carbohydrates would you NOT expect to find in a plant? chitin starch glucose cellulose Chitin is found in the exoskeletons of arthropods like this spider, not in plants.