Chemistry of Organic Molecules PDF

Chapter 3: The Chemistry of Organic Molecules Section 1 Chemistry in Biology Atoms, Elements, and Compounds Atoms ▪ Chemistry is the study of matter. ▪ Atoms are the building blocks of matter. ▪ Neutrons and protons are located at the center of the atom....

Chapter 3: The Chemistry of Organic Molecules Section 1 Chemistry in Biology Atoms, Elements, and Compounds Atoms ▪ Chemistry is the study of matter. ▪ Atoms are the building blocks of matter. ▪ Neutrons and protons are located at the center of the atom. ▪ Protons are positively charged particles. ▪ Neutrons are particles that have no charge. Section 1 Chemistry in Biology Atoms, Elements, and Compounds ▪ Electrons are negatively charged particles that are located outside the nucleus. Section 1 Chemistry in Biology Atoms, Elements, and Compounds Elements ▪ An element is a pure substance that cannot be broken down into other substances by physical or chemical means. ▪ There are over 100 known elements, 92 of which occur naturally. ▪ Each element has a unique name and symbol. Section 1 Chemistry in Biology Atoms, Elements, and Compounds The Periodic Table of Elements ▪ Horizontal rows are called periods. ▪ Vertical columns are called groups. Section 1 Chemistry in Biology Atoms, Elements, and Compounds Isotopes ▪ Atoms of the same element that have the same number of protons and electrons but have a different number of neutrons Section 1 Chemistry in Biology Atoms, Elements, and Compounds Radioactive Isotopes ▪ When a nucleus breaks apart, it gives off radiation that can be detected and used for many applications. Section 1 Chemistry in Biology Atoms, Elements, and Compounds Compounds ▪ A pure substance formed when two or more different elements combine ▪ Compounds are always formed from a specific combination of elements in a fixed ratio. ▪ Compounds cannot be broken down into simpler compounds or elements by physical means. Section 1 Chemistry in Biology Atoms, Elements, and Compounds Chemical Bonds ▪ Covalent bonds ▪ Chemical bond that forms when electrons are shared ▪ A molecule is a compound in which the atoms are held together by covalent bonds. Section 1 Chemistry in Biology Atoms, Elements, and Compounds Ionic Bonds ▪ Electrical attraction between two oppositely charged atoms or groups of atoms Section 2 Chemistry in Biology Chemical Reactions Reactants and Products ▪ A chemical reaction is the process by which atoms or groups of atoms in substances are reorganized into different substances. ▪ Clues that a chemical reaction has taken place include the production of heat or light, and formation of a gas, liquid, or solid. Section 2 Chemistry in Biology Chemical Reactions Chemical Equations ▪ Chemical formulas describe the substances in the reaction and arrows indicate the process of change. ▪ Reactants are the starting substances, on the left side of the arrow. ▪ Products are the substances formed during the reaction, on the right side of the arrow. Section 2 Chemistry in Biology Chemical Reactions ▪ Glucose and oxygen react to form carbon dioxide and water. Section 2 Chemistry in Biology Chemical Reactions Balanced Equations ▪ The law of conservation of mass states matter cannot be created or destroyed. ▪ The number of atoms of each element on the reactant side must equal the number of atoms of the same element on the product side. Section 2 Chemistry in Biology Chemical Reactions Energy of Reactions ▪ The activation energy is the minimum amount of energy needed for reactants to form products in a chemical reaction. Section 2 Chemistry in Biology Chemical Reactions ▪ This reaction is exothermic and released heat energy. ▪ The energy of the product is lower than the energy of the reactants. Section 2 Chemistry in Biology Chemical Reactions ▪ This reaction is endothermic and absorbed heat energy. ▪ The energy of the products is higher than the energy of the reactants. Section 2 Chemistry in Biology Chemical Reactions Enzymes ▪ A catalyst is a substance that lowers the activation energy needed to start a chemical reaction. ▪ It does not increase how much product is made and it does not get used up in the reaction. ▪ Enzymes are biological catalysts. Section 2 Chemistry in Biology Chemical Reactions ▪ The reactants that bind to the enzyme are called substrates. ▪ The specific location where a substrate binds on an enzyme is called the active site. Section 2 Chemistry in Biology Chemical Reactions ▪ The active site changes shape and forms the enzyme-substrate complex, which helps chemical bonds in the reactants to be broken and new bonds to form. ▪ Factors such as pH, temperature, and other substances affect enzyme activity. ⚫ Denaturing: extreme temperature and pH can change enzyme shape, rendering it useless. NORMAL SHAPE DENATURED SHAPE Chapter Chemistry in Biology Chapter Diagnostic Questions Identify the proteins that speed up the rate of chemical reactions. A. substrates B. enzymes C. ions 1. A 2. B D. reactants 3. C 4. D Chapter Chemistry in Biology Section 2 Formative Questions Which is a chemical reaction? A. a match burning B. salt dissolving C. water boiling D. gasoline evaporating 1. A 2. B 3. C 4. D Chapter Chemistry in Biology Section 2 Formative Questions Which chemical reaction is endothermic? A. B. 1. A 2. B Chapter Chemistry in Biology Section 2 Formative Questions How does an enzyme increase the rate of a chemical reaction? A. It acts as a reactant. B. It reduces the amount of heat produced. C. It increases the amount of product. 1. A D. It lowers the activation energy. 2.3. B C 4. D Chapter Chemistry in Biology Section 2 Formative Questions What occurs at the active site in the enzyme substrate complex? A. An exothermic chemical reaction takes place. B. Chemical bonds are broken and new bonds are formed. 1. A C. The enzyme gets used up in the reaction. 2. B 3. C D. The substrates provide energy for the4.enzyme. D Chapter Chemistry in Biology Chapter Assessment Questions Look at the following figure. ? Determine what the upward curve represents. A. activation energy B. reactants 1. A C. products 2. 3. B C 4. D D. enzymes Chapter Chemistry in Biology Chapter Assessment Questions Explain why chemical equations must be balanced. Answer: Chemical reactions require balance of mass. Therefore, the number of atoms of each element on the reactant side must equal the number of atoms of the same element on the product side. Chapter Chemistry in Biology Standardized Test Practice What is true of this chemical reaction? A. Energy is not needed to start the chemical reaction. B. Heat and/or light energy are released in this reaction. C. The activation energy is 1. 2. A B greater than the energy 3. C released. 4. D D. The energy of the products and the reactants is the same.