Lecture Campbell biology: Concepts and connections (Seventh edition) - Chapter 2: The chemical basis of life. In this chapter we will discuss: Elements, atoms, and compounds; chemical bonds; water's life supporting properties. | Chapter 2 The Chemical Basis of Life 0 Figure Chapter 2: Big Ideas Elements, Atoms, and Compounds Chemical Bonds Water’s Life- Supporting Properties Introduction Chemicals are the stuff that make up our bodies, the bodies of other organisms, and the physical environment. © 2012 Pearson Education, Inc. Introduction Life’s chemistry is tied to water. Life first evolved in water. All living organisms require water. The chemical reactions of your body occur in cells consisting of 70–95% water. © 2012 Pearson Education, Inc. ELEMENTS, ATOMS, AND COMPOUNDS © 2012 Pearson Education, Inc. Living organisms are composed of matter, which is anything that occupies space and has mass (weight). Matter is composed of chemical elements. An element is a substance that cannot be broken down to other substances. There are 92 elements in nature—only a few exist in a pure state. Organisms are composed of elements, in combinations called compounds © 2012 Pearson Education, . | Chapter 2 The Chemical Basis of Life 0 Figure Chapter 2: Big Ideas Elements, Atoms, and Compounds Chemical Bonds Water’s Life- Supporting Properties Introduction Chemicals are the stuff that make up our bodies, the bodies of other organisms, and the physical environment. © 2012 Pearson Education, Inc. Introduction Life’s chemistry is tied to water. Life first evolved in water. All living organisms require water. The chemical reactions of your body occur in cells consisting of 70–95% water. © 2012 Pearson Education, Inc. ELEMENTS, ATOMS, AND COMPOUNDS © 2012 Pearson Education, Inc. Living organisms are composed of matter, which is anything that occupies space and has mass (weight). Matter is composed of chemical elements. An element is a substance that cannot be broken down to other substances. There are 92 elements in nature—only a few exist in a pure state. Organisms are composed of elements, in combinations called compounds © 2012 Pearson Education, Inc. Table A compound is a substance consisting of two or more different elements in a fixed ratio. Compounds are more common than pure elements. Sodium chloride, table salt, is a common compound of equal parts of sodium (Na) and chlorine (Cl). Organisms are composed of elements, in combinations called compounds © 2012 Pearson Education, Inc. Figure Sodium Chlorine Sodium chloride About 25 elements are essential to life. Four elements make up about 96% of the weight of most living organisms. These are oxygen, carbon, hydrogen, and nitrogen. Trace elements are essential but are only needed in minute quantities. Organisms are composed of elements, in combinations called compounds © 2012 Pearson Education, Inc. CONNECTION: Trace elements are common additives to food and water Some trace elements are required to prevent disease. Without iron, your body cannot transport oxygen. An iodine deficiency prevents production of thyroid hormones, resulting in .
