CHEMISTRY OF LIVING THINGS

1. Chapter 2 CHEMISTRY OF LIVING THINGS

2. CHEMISTRY • Defined as the study of the structure of matter and the composition of substances, their properties, and their chemical reactions • Biochemistry is the study of chemical reactions of living things © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

3. MATTER AND ENERGY • Matter is anything that has weight and occupies space; it is neither created nor destroyed • Energy is the ability to do work or to put material into motion and exists in the body as: • Potential energy • Kinetic energy © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

4. ATOMS • An atom is the smallest piece of an element • Atoms are made of subatomic particles • Protons have a positive charge • Neutrons have no charge • Electrons have a negative charge © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

5. ATOMS • Isotopes are atoms of a specific element with the same number of protons but a different amount of neutrons • Radioactive Isotopes are unstable and may decay © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

6. ELEMENTS • Atoms that are alike combine to form elements • There are 92 elements found naturally and each is represented by a chemical symbol or abbreviation © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

7. COMPOUNDS • Organic compounds are compounds found in living things containing the element carbon • Molecules are the smallest units of compounds that retain its properties and remain stable © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

8. IONS AND ELECTROLYTES • Ions are atoms that have more protons than electrons; creating a positive charge • Electrolytes are atoms that have more electrons than protons; creating a negative charge © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

9. TYPES OF COMPOUNDS • Inorganic Compounds • Made of molecules that do not contain carbon (C) • Organic Compounds • Always contain the element carbon (C) • 4 Groups of organic compounds are: • Carbohydrates • Proteins • Lipids • Nucleic acids © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

10. CARBOHYDRATES • All carbohydrates are compounds of carbon, hydrogen, and oxygen • 3 Groups of carbohydrates: • Monosaccharides • Disaccharides • Polysaccharides © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

11. LIPIDS • Lipids contain less oxygen than hydrogen • Examples of lipids: • Fats • Phospholipids • Steroids © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

12. PROTEINS • Proteins are among the most diverse and essential organic compounds found in all living things • Amino acids are the small units that make up protein molecules • Enzymes are specialized protein molecules that help control chemical reactions in a cell © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

13. NUCLEIC ACIDS • Nucleic acids are the largest known organic molecules; made from thousands of repeating subunits called nucleotides • There are two major types of nucleic acids: • DNA • RNA © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

14. ACIDS, BASES, AND SALTS • Acids are substances that yield hydrogen ions in solution • Bases are substances that ionize into negatively charged hydroxide ions and positively charged ions of metal when dissolved in water • Salts are formed when acids and bases are combined © 2004 Delmar Learning, a Division of Thomson Learning, Inc.

15. PH SCALE • pH measures acidity or alkalinity of a solution • The pH scale ranges from 0 to 14 • A pH between 0 and 6.9 is acidic • A pH between 7.1 and 14 is alkaline • A pH of 7.0 is neutral as it contains the same number of hydrogen and hydroxide ions © 2004 Delmar Learning, a Division of Thomson Learning, Inc.