CHEMISTRY OF LIFE

ALL organic compounds contain the element carbon. Remember, carbon has a valence of 4. Ie. Each carbon atom can form 4 bonds with other atoms. These bonds can be: ( strong ) ( stronger ) ( strongest )

Carbon atoms bond together to form: Straight Chain Branched Chain Ring

Isomer – compounds that have the same molecular formula but different structures. Ex. C6H12O6

Monomer – a single molecule that is a building block for larger molecules. Polymer – a large molecule formed when monomers bond together. To form a polymer, a condensation reaction is necessary and H2O is released. To break apart a polymer, a hydrolysis reaction must occur and H2O is added.

Carbohydrates Lipids Proteins Nucleic Acids There are 4 major types of organic compounds that make up living things: Carbohydrates Lipids Proteins Nucleic Acids

CARBOHYDRATES

ALL carbohydrates are composed of carbon, hydrogen and oxygen in a 1 : 2 : 1 ratio. Ex. C6H12O6 Carbohydrates can appear in 3 different forms: 1. Monosaccharides – These are simple sugars. “mono” means one and “saccharide” means sugar. * These are the monomers of all carbohydrates.

Disaccharides – Two monosaccharides bonded together. “di” means two. Ex. Sucrose (table sugar ) comes from glucose + fructose.

Polysaccharides – “poly” means many monomers bonded together to form a large molecule. These a complex sugars and starches. Used for quick energy. Stored in: Plants – seeds, bulbs (potatoes, turnips) Mammals – liver in the form of glycogen. * Plant cell walls as cellulose (shape & support).

LIPIDS

Lipids are fats, oils, waxes, cholesterol, and steroids. Monomer is a fatty acid. Composed of CHO but not in a 1 : 2 : 1 ratio. Ex. Beef fat (C57H110O6) hydrophobic – do not dissolve in water. Used for energy storage, insulation and protection. Fats – Saturated – solid at room temp. UNHEALTHY Ex. Bacon grease, butter Unsaturated – liquid at room temp. HEALTHY Ex. Olive oil

PROTEINS (Aka – polypeptides)

Proteins are complex molecules made of CHO + Nitrogen and sometimes Sulfur. Monomer is an amino acid. Amino acids are linked together by peptide bonds. Proteins build tissues & organs and help conduct chemical reactions.

NUCLEIC ACIDS

Nucleic acids are complex macromolecules that store genetic info. Made of CHO + N + Phosphorous Monomer is a nucleotide. Two nucleic acids: DNA – deoxyribonucleic acid – master code of life. RNA – ribonucleic acid – important in protein synthesis.

The ENZYMES

Enzymes are proteins. Enzymes are biological catalysts, ie. Speed up chemical reactions by lowering the activation energy needed to start the reaction. Most enzymes end in “ase”. Ex. Protease, lactase, maltase.

The substrate must fit exactly into the enzyme’s active site for Enzyme operation is similar to a “lock & key”. Enzyme substrate E-S complex enzyme products The substrate must fit exactly into the enzyme’s active site for the reaction to occur. Enzymes are not generic – different enzymes for different reactions. The enzyme is reusable.

Denatured Enzymes Enzyme shape has been changed. Denatured enzymes will no longer work. Enzymes can be denatured by: 1. increases in temperature 2. changes in pH HOW FAST? Enzymes can speed up chemical reactions by as much as 10,000,000,000 X’s. Ie. A reaction that might take 1500 years to complete – happens in 5 seconds with an enzyme!