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Chapter 2 Concepts of Matter and Energy MatterFound Can in either solid, liquid, or gas states. be changed physically or chemically EnergyKinetic Energy- Potential All Energy- forms of energy exhibit both kinetic and potential work capacities Forms of energy: -Chemical-Electrical-Mechanical-RadiantEnergy can easily be converted from one form to another (with a few exceptions). -Energy conversion is not very efficient, lose a lot to heat 1 Composition of Matter ElementA list of the known elements are organized in the periodic table AtomAtomic symbolAtomic Structure Protons- Neutrons- Electrons- Planetary and Orbital Models of the atom- See figure 2.1 Identifying atoms- varying number of protons, neutrons, and electrons makes each atom different. Atomic Number- Atomic Mass- Atomic Weight- -Isotope- varying forms of an individual atom, the isotope of each atom has the same number of protons and electrons, but varies in number of neutrons. 2 Molecules and Compounds MoleculeCompoundChemical Bonds and Chemical Reactions Chemical ReactionBond Formation- When atoms unite chemically, chemical bonds are formed. Role of electrons in bonding- outer most electrons are involved in bonding. What makes a chemical bond? 1) 2) Three types of chemical bonds Ionic bonds- Covalent bonds- Hydrogen bonds- Patterns of Chemical Reactions Synthesis reaction- Decomposition Exchange reaction- reaction3 Biochemistry: The chemical composition of living matter Inorganic CompoundsWater- most abundant inorganic compound in the body, 2/3’s of body weight. -Heat Capacity-Polarity/Solvent properties-Chemical reactivity-CushioningSalts- ionic compounds, when dissolved, easily separate into their ions. ElectrolytesAcids- a substance that can release hydrogen ions (proton donor) -have a sour taste -can dissolve metals -strong acids dissociate completely HCl H+ + Cl-weak acids dissociate incompletely H2CO3 H+ + HCO3-+ H2CO3 Bases- a substance that picks hydrogen ions (proton acceptor) -have a bitter taste -feel slippery -NaOH Na+ + OHAcid/Base Exchange Reaction: Results in water and a salt HCl + NaOH H2O +NaCl 4 pH: Acid/Base Concentrations -pH Scale- range from 0 to 14. -based on the concentration of hydrogen and hydroxyl ions in solution. -1 is the most acidic, 14 the most basic, 7 is neutral. -a change in 1 unit on the pH scale represents a 10-fold change in hydrogen ion concentration. -buffers- chemicals that can regulate a solution’s pH. Organic Compounds- larger, complex compounds that contain carbon. Carbohydrates- -Usually have a ratio of 2 H’s to 1 O. Glucose C6H12O6 or Ribose C5H10O5 -Classified as: -Monosaccharides-Disaccharides-Polysaccharides-Carbohydrates are a good source of food energy for cells. -During glycolysis, glucose is broken down into water and CO2, and ATP, the high energy molecule used in most cellular reactions. Lipids- large compounds with carbon, hydrogen, and oxygen in various proportions. -Usually have a lot more C and H than O (tristearin C57H110O6) -Do not easily dissolve in water, but in other lipids, alcohol, and acetone. -Classified into: -Triglycerides (neutral fats)-saturated or unsaturated 5 -body’s most abundant and concentrated source of usable energy. -Phospholipids-has polar properties -found in cellular membranes -Steroids-Cholesterol is most important of steroids -Used to make vitamin D, some hormones, and bile salts. Proteins- -over 50% of organic matter in the body -multi-functional -Building blocks of proteins are amino acids -can range from 50 to 1000’s of amino acids in structure. -The sequence in which the amino acids are placed determines the structure and function of that specific protein. -Fibrous or Structural Proteins-Globular or Functional ProteinsEnzymes-contain a specific structure that allows for binding to a specific substrate. The enzyme does not get used up during these reactions, and is very specific in the reaction is helps to carry out. 6 Nucleic Acids- -make up genes, which carries the blueprint for life -building blocks are nucleotides -five different nucleotides: -guanine, cytosine, adenine, thymine, uracil -DNA contains GCAT, RNA contains GCAU ATP- -high energy molecule composed of C, O, H, N, P -without ATP, no biologic reactions would take place -energy is released when the outermost phosphate group broken off, high energy is stored in that bond. 7