 The energy you use comes from the carbohydrates in food
 Your body changes carbohydrates into glucose– a form you can use for immediate energy
 Your body also stores some glucose in muscles and liver for later use

 An organic compound that is the body’s main source of energy
 Its name breaks down into tow of the main elements in the structure– Carbon (C) and
Hydrogen (H)
 Carbohydrates also contain oxygen (O)
 Empirical Formula: C n
H
2n
O n

 We will look at these structures more later

 They are found mainly as foods from plant sources such as:
 Fruits
 Vegetables
 Grain products
 Peas

 They are produced by plants through the process of photosynthesis
 Plants absorb energy from the sun, water through the roots and carbon dioxide from the air
 A chemical reaction occurs which produces oxygen and glucose
CO
2
+ H
2
O + energy = O
2
+ C
6
H
12
O
6

 Glucose is the basic sugar molecule from which all other carbohydrates are built
 Plants can convert sugar into other sugars, starches, and fiber
 Glucose will convert to sugar first then to starch as plants mature

Carbohydrate
Disaccharides
Simple
Monosacharides
Fiber
Complex
Starch

 Simple carbohydrates are one or two sugars in very small molecules
 Complex carbohydrates are starches and fiber– large molecules made of many simple carbohydrates

 Sugars exist in various crystalline structures
 Contain –OH groups called hydroxyl groups
 A hydroxyl group is a combination of hydrogen and oxygen atoms, containing one atom of each

 Sugars are given the name saccharide
 A saccharide is a sugar or substance made from sugar
 Two types of simple sugar saccharides
 Monosaccharide
 disaccharide

 Single molecule of sugar
 Three examples:
 Glucose- the “building blocks” of all sugars
 Fructose- found in fruits and tree sap
 Galactose- Not found free in nature, but bonded to something else; found in yogurt and aged cheese

 Made of two monosaccharides bonded together
 Three examples:
 Sucrose
 Glucose + Fructose
 Table Sugar
 Maltose
 Glucose + Glucose
 Cereals & Grains
 Lactose
 Glucose + Galactose
 Milk

 Polymers form when many single sugars join together chemically
 Include: Starch & Cellulose
 Bonded together through glycosidic covalent bonds

 Storage molecule in plants
 Provides the majority of food calories consumed by people worldwide
 Plants store energy in amylopectin
 Animals store energy in the muscles and liver as glycogen
 For long term storage, animals convert the food calories from carbohydrates to fat
 Humans store fat in adipose tissue

 Found in plant cell walls and is the most abundant carbohydrate on Earth
 Source of dietary fiber
 Cannot be digested by animals