10/15/13 Objective: What are the properties of Lipids? Chapter 5: The Molecules of Life Do Now: What can happen to sugar if not used for energy?

Lipids lipids: class of compounds that are hydrophobic (water- fearing) and nonpolar –Made of glycerol and fatty acid –Part of cell membrane –store energy

Fats fats(triglyceride):) made of glycerol attached to 3 fatty acids(long hydrocarbon chains) –Solid or liquid –Fatty tissues cushion organs and provide body with insulation saturated fats: all fatty acid chains contain the maximum possible number of hydrogen atoms –All single bonds –Animal fats (solid at room temp) unsaturated: less than max. number of H atoms in one or more fatty acid chains –Some double bonded –Most plant and fish oils (liquid at room temp)

Steroids steroids: carbon skeleton forms 4 fused rings –Different functional groups attached to rings Examples: Cholesterol, Sex hormones

Cholesterol cholesterol: essential molecule found in cell membranes –Help maintain membrane structure

Phospholipids Major part of cell membrane

5.4 Proteins protein: a polymer constructed from monomers called amino acids. –Ex: Enzymes, hormones, cell receptors, immune defense

Protein Structure amino acid: monomer that consists of a central carbon atom bonded to four partners (carbon forms 4 bonds)- a carboxyl and amino group Polypeptide: chain of amino acids that make up a protein –Made by dehydration synthesis

Shape polypeptides are precisely twisted, folded, and coiled into a unique shape for each protein Shape of protein determines how it will function

Denaturation Denaturation: unfavorable change in pH, temperature, or other quality of the environment that causes the protein to unravel and lose shape –(ex. frying an egg; albumin is egg white which turns from clear to white)

Enzymes enzymes: proteins that act as organic catalysts –Lowers activation energy pH and temp can affect function

Catalysts Catalysts: compounds that speed up chemical reactions

How Enzymes Work substrate - a specific reactant acted upon by an enzyme the shape of the enzyme fits the shape of only particular substrate active site - where enzymes binds to substrate Substrates are the reactants. Lactose is the substrate, lactase is the enzyme.

Enzyme Function Describe what is occurring in the picture:

Enzyme Function

Nucleic Acids DNA: dexoyribose nucleic acid RNA: ribose nucleic acid