Carbohydrates are another form of biological molecule. They are an important energy source in cellular respiration. They are composed of monosaccharides, which is the basic molecular unit or monomer, all of which contain three molecules:
- carbon (C)
- hydrogen (H)
- oxygen (O)
These molecules bind together in a specific ratio: Cx(H2O)y
Monosaccharides can join together to make polymer chains:
- disaccharides are composed of two sugars
- trisaccharides are composed of three sugars
- polysaccharides are composed of many sugars
Digestion of Carbohydrates
Carbohydrates are broken down by enzymes. In digestion, different enzymes are responsible for breaking down different carbohydrates.
| Name | Location | Function |
| Salivary amylasePancreatic amylaseMaltase
Sucrase Fructose Lactase |
Secreted by the salivary glands in the mouth when you eat.Secreted from the pancreas into the small intestineProduced by the small intestineProduced by the small intestine
Produced by the small intestine Produced by the small intestine |
Breaks down polysaccharides into maltose (disaccharides)Breaks down polysaccharides into maltose (disaccharides) and maltriose (trisaccharides)Breaks down maltose into glucoseBreaks down sucrose into glucose
Breaks down lactose into glucose Breaks down lactase into galatose |