Biology Class 3

“Life’s Chemistry”

Biology 3rd Class

Terms: Polymers – large molecules that are constructed by bonding smaller molecules (monomers) • Dehydration synthesis – the process of building polymers (taking water away) • Hydrolysis – the process of breaking down polymers (adding water) Major Organic Molecules (carbon and hydrogen) *Carbohydrates * Lipids * Proteins * Nucleic Acids

1. Carbohydrates a. Contain Carbon, Hydrogen, and Oxygen b. Function to store energy and provide support c. Building blocks (monomers) are monosaccharides Monosaccharides d. simple sugars e. C, H, and O ratio is 1:2:1 Disaccharides f. simple sugars composed of 2 linked monosaccharides (dehydration synthesis) g. common disaccharides include: maltose, and lactose Polysaccharides h. complex carbohydrates composed of up to hundreds of monomers

2. Lipids a. contain C, H, O b. do not dissolve in water Tryglycerides i. composed of glycerol linked to 3 fatty acid chains ii. function to cushion organs, as insulation and long term energy storage (adipose tissue) Saturated Fats -tend to be liquid at room temp

Unsaturated Fats – tend to be solid at room temp (lipids in plants are generally less saturated than those found in animals) Phospholipids o lipid bonded to a phosphate group o major component of cell membranes Sterols o lipids that have 4 interconnected rings  example: vitamin D, cortisone, estrogen, cholesterol Waxes o fatty acids combined with hydrocarbons o help waterproof fur, feathers, leaves, and fruits

3. Proteins a. contain C, H, O, N, (S) b. monomers are amino acids (amino acids contain a central carbon, carboxyl group (COOH), Amino Group (NH2), and R group) R = variable Proteins have a three dimensional shape (conformation): • Primary (1º) structure – amino acid sequence of polypeptide chain • Secondary (2º) structure – coiling and folding produced by hydrogen bonds • Tertiary (3º) structure – shape created by interactions between R groups • Quarternary (4º) structure – shape created by interconnections between two or more polypeptides *** A change to the shape of a protein causes denaturation 1. Enzymes o Enzymes can be used to join substrates or break apart substrates o The shape of the enzymes active site is critical to proper functioning

4. Nucleic Acids • •

contain H, C, O, N, P monomers are nucleotides

The five types of Nucleic Acids are: Guanine Cytosine Thymine Adenine Uracil A nucleotide consists of a sugar (ribose or deoxyribose), a phosphate, and one of five nitrogenous bases.

Important to remember: What are the monomers of each major organic molecule? What are the functions of each molecule along with examples of such?