Macromolecules Macromolecules are large, functional, carbon based structures that serve specific functions in living organisms. – 4 basic types Carbohydrates Lipids Proteins Nucleic Acids

Carbohydrates & Lipids The individual pieces that make them are called monomers. – 2 monomers make a dimer – 3 make a trimer... – many together form a polymer – Roughly different monomers combine to make up the thousands of different macromolecules present in the cells.

Carbohydrates Carbohydrates are sugars. – Used as the main source of energy in living things Sugars can be single units which are monosaccharides (simple sugars), as disaccharides, or as long chains which are polysaccharides. Monosaccharides (monos - single, sacchar - sugar) – empirical formula of (CH 2 O) n – Common forms… glucose, galactose, fructose Molecular formula C 6 H 12 O 6 Are isomers of each other… same formula but different arrangement

Synthesis of Carbohydrates Can be formed through a condensation reaction – Each monosaccharide is added through the process of dehydration synthesis forming a glycosidic linkage Removal of a water molecule when forming a bond Can be separated through hydrolysis – Addition of water to break the bond

Common Sugars Common Disaccharides – Maltose… glucose + glucose – Sucrose… glucose + fructose – Lactose… glucose + galactose Common Polysaccharides – Starch … plant storage for food – Cellulose… rigid structural material in plants Not digestible in animals – Glycogen… animal storage for food

Lipids Lipids are macromolecules connected by ester linkage (via dehydration synthesis) between a glycerol molecule and 3 fatty acid chains (triglyceride or triacylglycerol). Glycerol – 3 carbon alcohol molecule each carbon is attached to a hydroxyl (-OH) functional group Fatty acid – chain of about carbon atoms – has a carboxyl g roup on the side that attaches to the glycerol – very hydrophobic (water hater!) – a fatty acid with no double bonds is said to be saturated most animal fats (lard, butter,...) solid at room temp chains can tightly pack (linear in shape) a diet rich in saturated fats leads to atherosclerosis …hardening of the arteries – a fatty acid with at least one double bonds is said to be unsaturated

Lipids Are used for… – Storage of energy… Storage of fat in humans is called adipose – Cell membranes Phospholipid bilayer – Chemical messengers… steroids – Insulation and shock absorption