Chemistry

CHAPTER 8 An Introduction to Metabolism Metabolism is the totality of an organism?s chemical reactions Manage the materials and energy resources of a cell Catabolic pathways release energy by breaking down complex molecules into simpler compounds Eg. digestive enzymes break down food ? release energy Anabolic pathways consume energy to build complex molecules from simpler ones Eg. amino acids link to form muscle protein ENERGY = CAPACITY TO DO WORK Kinetic energy (KE): energy associated with motion Heat (thermal energy) is KE associated with random movement of atoms or molecules Potential energy (PE): stored energy as a result of its position or structure Chemical energy is PE available for release in a chemical reaction Energy can be converted from one form to another

Chapter 4 Carbon and the Molecular Diversity of Life I. Importance of Carbon Organic chemistry: branch of chemistry that specializes in study of carbon compounds Organic compounds: contain Carbon (& H) Major elements of life: CHNOPS Carbon can form large, complex, and diverse molecules II. Diversity of Carbon It has 4 valence electrons (tetravalence) It can form up to 4 covalent bonds Most frequent bonding partners: H, O, N II. Diversity of Carbon Bonds can be single, double, or triple covalent bonds. II. Diversity of Carbon Carbon can form large molecules 4 classes of macromolecules: carbohydrates, proteins, lipids, nucleic acids II. Diversity of Carbon Molecules can be chains, ring-shaped, or branched II. Diversity of Carbon Forms isomers