1.4 Carbohydrates

Carbohydrates

includes sugars and polymers of sugar

contain a carbonyl group and many hydroxyl groups

C, H, and O

Monosaccharides

monomers of carbohydrates

simple sugars

1:2:1 ratio, starting with CH2O

most common is glucose

nutrients and fuel for cells

used in cellular respiration

can serve as building blocks for amino acids, or as monomers for di- and polysaccharides

Disaccharides

two monosaccharides joined together by covalent bonds

most common is sucrose

monomers of sucrose are glucose and fructose

plants transfer carbohydrates from roots to leaves in the form of sucrose

Polysaccharides

polymers of carbohydrates

complex carbohydrates

polymers with many sugars joined via dehydration reaction

The storage polysaccharides are starch and glycogen

plants store starch(polymers of glucose monomers) to store excess glucose

animals store glycogen(polymer of glucose), stored in liver and muscle cells

structural polysaccharides are cellulose and chitin

cellulose is a tough substance that forms plant cell walls

chitin forms the exoskeleton of arthropods