Notes Carbon Compounds Section 2-3

Organic Molecules Molecules containing 2 or more atoms of carbon Carbon is very versatile Carbon covalently bonds with up to 4 other atoms Carbon can bond with carbon to form: Chains Branches Rings

Organic Molecules Carbon can form single, double or triple bonds Carbon forms important biological molecules

Macromolecules: “giant molecules” There are four classes of organic (carbon based) macromolecules Carbohydrates Lipids Proteins Nucleic Acids

Macromolecules are polymers What is a polymer? Poly = many; mer = part. A polymer is a large molecule consisting of many smaller sub-units bonded together.What is a monomer? A monomer is a sub-unit of a polymer Three of the organic macromolecules are polymers

1. Carbohydrates Carbo = carbon, hydrate = water; carbohydrates have the molecular formula (CH2O)n 1:2:1 ratio Common types: Sugar Starch

Carbohydrates Functions: Store chemical energy for cellular use Structural support in cells e.g. cellulose cell wall in plants

Carbohydrates Monosaccharide – monomer of 3-7 carbons e.g. glucose, fructose, galactose Disaccharide - two mono’s linked e.g. sucrose = glucose + fructose Polysaccharides – Many mono’s linked e.g. starch

Examples of Disaccharides: Lactose = glucose + galactose Sucrose = glucose + fructose

Polysaccharides

2. Lipids Generally hydrocarbons (made of hydrogen and carbon) Not a polymer Not water soluble

Lipids Common names: Fats Oils Waxes Steroids

Lipids Functions: Energy storage – long term Membrane structure Waterproofing Insulation Shock absorbing Chemical messengers (hormone action)

Common Lipids = Triglycerides Glycerol + 3 fatty acids

Fatty Acids: Saturated or Unsaturated 1. Saturated fats: “saturated with hydrogen” have only single C-C bonds solid at room temp most animal fats 2. Unsaturated fats : liquid at room temp double bonds between carbons allows for “kinks” in the tails most plant fats 3. Polyunsaturated = many double bonds

Which type of fatty acid is this?

Which type of fatty acid is this? Saturated fatty acid

Unsaturated fatty acid Good Job!! Saturated fatty acid Unsaturated fatty acid

3. Nucleic Acid Made of elements carbon, hydrogen, oxygen, nitrogen and phosphorus (CHONP) Polymers of nucleotides Nucleotide

Nucleotide Composed of: a. 5-Carbon sugar b. Phosphate group c. Nitrogen base

Nucleic Acids Two kinds: DNA: RNA: Double stranded Sugar deoxyribose Contains genes which code for proteins Hereditary information RNA: Single stranded Functions in synthesis of proteins coded for by DNA Sugar ribose RNA DNA

4. Protein Polymer of amino acids Made of elements carbon, hydrogen, oxygen and nitrogen (CHON) Amino acids held together with peptide bonds Proteins called polypeptides

Structure of Amino Acid Monomers Carbon covalently bonded to: Hydrogen Amino group (NH3) Carboxyl group (COOH) Variable R group specific to each amino acid 20 common amino acids

Peptide Bonding

Protein functions Enzymes accelerate chemical reactions Structural e.g. keratin (the protein found in hair and nails) collagen (the protein found in connective tissue). Cell identity Membrane transport Cell movement

Shape important to Protein Function Changing shape changes function 4 levels of shape Primary Secondary Tertiary Quaternary

© 1999 Addison Wesley Longman, Inc.