Biochemistry Molecules of Life.

Organic Chemistry Organic Compounds - compounds synthesized by cells and contain carbon ---Four types of organic molecules (biomolecules) exist in organisms: carbohydrates lipids proteins nucleic acids Organic compounds are made from a carbon skeleton which can vary in length, be branched or unbranched, have double bonds which vary in location, or may be arranged in rings.

Carbon Bonding Carbon has 4 e- on outer shell therefore it will for 4 covalent bonds to become stable. Three types of bonds are generally formed: Straight: Branched: Ring:

Carbon Cont. Carbon can also pair with another carbon molecule for form: Single Bonds Double Bonds Triple Bonds

MACROMOLECULES 1. Carbohydrates, lipids, proteins, and nucleic acids are called macromolecules because of their large size. 2. The largest macromolecules are called polymers, constructed by linking many of the same type of small subunits, called monomers. *****Examples: amino acids (monomers) are linked to form a protein (polymer); many nucleotides (monomers) are linked to form a nucleic acid (polymer). 3. Dehydration reactions to synthesize macromolecules. In a dehydration reaction, a water molecule is removed and a covalent bond is made between two atoms of the monomers. Ex. Glucose + Fructose = Sucrose 4. Hydrolysis ("water breaking") reactions break down polymers in reverse of dehydration; 5. Enzymes are molecules that speed up chemical reactions by bringing reactants together; an enzyme may even participate in the reaction but is not changed by the reaction.

CARBOHYDRATES An organic compound composed of Carbon, Hydrogen and Oxygen with a ratio of 2 H : 1 O Types of Carbs: monosaccharides - simple ring sugars. (glucose and fructose and galactose) See Photo

Carbs Cont. disaccharides - two monosaccharides combined, sucrose and lactose (happens via condensation or dehydration reaction) polysaccharides - polymers (long chains of repeating units) of monosaccharides, these are energy storing molecules starch (plants) and glycogen (animals)

LIPIDS (FAT) Large Non-Polar organic molecules that do not dissolve in water. Higher Ratio of Carbon to hydrogen Types of Lipids Fatty Acids: Amphipathic, unbranched carbon chains Amphipathic: Contains both a hydrophillic and hydrophobic region on same molecule.

Lipids Cont Phospholipids - form membranes of cells (See Drawing) Steroids (cell messengers) - composed of 4 rings of carbon, also includes Chlolesterol, examples: testosterone, estrogen Waxes (protection & waterproofing) Triglycerides (fats and oils) - fats are made of chains of fatty acids Saturated fats contain no double bonds Saturated fats solid at room temperature Unsaturated fats have double bonds are liquid at room temperature

Proteins Organic Compounds Composed of Carbon, Hydrogen, Oxygen and Nitrogen. Created by the bonding of monomers

Protein Cont. There are 20 different Amino Acids and they are the Building Blocks (monomers) of Proteins. Amino Acids are composed of Carbon bonded to 4 other Atoms. (see prior picture) The “R” group (Functional group) determines the differences in each Amino Acid. The bond between each Amino Acid is called a dipeptide and is the result of a Condensation reaction.

Nucleic Acids NUCLEIC ACIDS: Very Large Complex organic molecules that store important information in the cell. Informational polymers (Contain Genetic Information) DNA(deoxyribonucleic acid) & RNA (ribonucleic acid) Structure of DNA Composed of Nucleotides 5 carbon sugar (deoxyribose) Nitrogen base (adenine, thymine, guanine, cytosine) Phosphate group