Biology is designed for multi-semester biology courses for science majors. It is grounded on an evolutionary basis and includes exciting features that highlight careers in the biological sciences and everyday applications of the concepts at hand. To meet the needs of today’s instructors and students, some content has been strategically condensed while maintaining the overall scope and coverage of traditional texts for this course. Instructors can customize the book, adapting it to the approach that works best in their classroom. Biology also includes an innovative art program that incorporates critical thinking and clicker questions to help students understand—and apply—key concepts.

By the end of this section, you will be able to:Describe the four major types of lipidsExplain the role of fats in storing energyDifferentiate between saturated and unsaturated fatty acidsDescribe phospholipids and their role in cellsDefine the basic structure of a steroid and some functions of steroidsExplain the how cholesterol helps to maintain the fluid nature of the plasma membrane

By the end of this section, you will be able to:Describe the four major types of lipidsExplain the role of fats in storing energyDifferentiate between saturated and unsaturated fatty acidsDescribe phospholipids and their role in cellsDefine the basic structure of a steroid and some functions of steroidsExplain the how cholesterol helps to maintain the fluid nature of the plasma membrane

All cells, organs and tissues of a living organism are built of molecules. Some of them are small, made from only a few atoms. There is, however, a special class of molecules that make up and play critical roles in living cells. These molecules can consist of many thousands to millions of atoms. They are referred to as macromolecules (or large biomolecules).