Organic vs. Inorganic All compounds can be separated into two groups: Doesn’t contain carbon Non-living Examples: Oxygen gas, metals, rocks, water Organic Contains carbon Living (or dead) Examples: wood, grass, diamonds, petroleum

Polymerization Monomers One unit of a compound Polymers Many monomers combine to make a polymer Macromolecules Many large molecules combined

Carbohydrates Made of C, H, O Functions Types Main energy source in organisms Structural component in plants (CELLULOSE) Types Sugars gives off energy when broken down Ex. Sucrose, fructose, glucose Starches used as a storage molecule for sugars Ex. Bread, rice, pasta, corn

Lipids Made of C, H, O Commonly called fats, oils, waxes Functions in the form of glycerol and fatty acid chains Commonly called fats, oils, waxes Functions Storage of energy Parts of biological membranes Water proof coverings Chemical messengers (steroids) Insoluble in water Ex. Lard, butter, oil, hormones, steroids

Saturated fats (lard) lack double bonds Fatty acid Figure 3.8B Figure 3.8C Saturated fats (lard) lack double bonds They are solid at room temperature

Nucleic acids Made of C, H, O, N, P Monomers are called nucleotides Nucleotides are made up of a 5-carbon sugar, phosphate group and a nitrogen base Functions Store hereditary information Transmit hereditary information Two types RNA (ribonucleic acid) DNA (deoxyribonucleic acid) Nitrogenous base (A) Phosphate group Sugar Figure 3.20A

RNA vs DNA There are THREE main differences between DNA & RNA The sugar In DNA its DEOXYribose sugar In RNA it’s Ribose sugar Number of strands DNA is usually double stranded RNA is ONLY single stranded Nitrogen Bases DNA Adenine pairs with Thymine Guanine pairs with Cytosine RNA Adenine pairs with Uracil

Proteins Made of C, H, O, N (P, S) Monomers are amino acids Functions There are 20 different amino acids that combine in different ways to make millions of proteins The most diverse macromolecules Functions Control the rates of chemical reactions (enzymes) Regulate cell processes Used to form bone & muscles Transport substances into or out of cells Help fight disease Amino group Carboxyl (acid) group Figure 3.12A

Primary structure Secondary structure Tertiary structure Amino acid Secondary structure Hydrogen bond Pleated sheet Alpha helix Figure 3.15, 16 Tertiary structure Polypeptide (single subunit of transthyretin) Quaternary structure Transthyretin, with four identical polypeptide subunits Figure 3.17, 18

Enzymes Special PROTEINS Act as biological CATALYSTS: speed up the rate of a chemical reaction by lowering the activation energy of the reaction Activation Energy: energy needed to transform reactant substances into product substances Reaction pathway without enzyme Activation energy Activation energy with enzyme Reactants Products A substance that an enzyme reacts on is called the enzyme’s substrate Only a small part of an enzyme molecule, called the active site, actually binds to the substrate

Enzymes are specific in the reactions they catalyze (Lock and Key model) They will only catalyze one specific substance, in one direction (a -> b, but not b -> a) They are reusable A substance that an enzyme reacts on is called the enzyme’s substrate Only the active site in the enzyme actually binds to the substrate Enzymes end in –ase Example: amylase, helicase

Factors Affecting Enzyme Activity: PH Temperature Salt concentration Enzymes lose their shape easily (denature) Shape is very important in enzyme activity!