BSC 181 1st Edition Lecture 4Outline of Last Lecture I. Matter A. Definition of Matter II. Atoms and Elements A. Definitions of Atoms and ElementsIII. Models of the AtomA. Identifying ElementsIV. Mixtures and CompoundsOutline of Current Lecture V. Chemical BondsVI. Chemical ReactionsVII. Compounds ContinuedVIII.Acids and BasesA. Acid/Base NeutralizationB. Acid/Base HomeostasisIX. BuffersCurrent LectureChemical Bonds: are energy relationships between reacting atoms and their electrons. Basically it’s atoms sharing, giving, or gaining electrons with or from other atoms. In the last lecture we talked about how the Electrons are in orbitals around the nucleus. This comes back into play here. Each orbital can be called an electron shell, or energy level. There can be up to seven electron shells for each atom, and the outer most electron shell is called the valence shell. There are three major types of chemical bonds. There is the Ionic Bond, Covalent Bond, and Hydrogen Bond. Bonds are formed because atoms want to have eight electrons, and they will try to get them whether that means sharing, giving, or gaining those electrons. The Ionic Bond: most of the ionic compounds that we see are salts. Covalent Bond: This is where two or more valence electrons are shared between atoms, it’s like the two atoms are “coexisting” with each other. There are two types of covalent bonds. Polar covalent bonds (polar bonds), and nonpolar covalent bonds (nonpolar bonds)These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Polar Bonds (aka Dipole Bond): the easiest way that I remember these is that I think of the north and south pole, they are on opposite ends of the planet and they both are different poles. In polar bonds it works kind of the same way. Thereis an unequal sharing of electrons in these polar bonds that cause one end of the molecule to be more negatively charged and the other end of the molecule to be more positively charged. Nonpolar Bonds: Having a nonpolar bond is just the opposite. There is no clear negative and positive side to the molecule because the electrons are shared equally.Hydrogen Bond: a hydrogen bond is not a true bond, it’s more like two atoms that are attracted to each other rather than bonded to each other. You can think of a hydrogen bonds strength like Velcro. It’s pretty weak when there is not a lot attached, but when you add more and more of it gets stronger. If the Velcro example didn’t work, you can think of it as that there are strength in numbers and more bond there is the stronger it is. We see Hydrogen bonds in protein and DNA.Chemical Reactions: There are three different types of chemical reactions that was talked aboutin lecture. Keep in mind that there are more than just these three. The ones that were covered in class are called Synthesis (combination) reactions, Decomposition Reactions,Exchange (displacement) reactions, and Oxidation-Reduction Reactions.Synthesis (combination) Reactions: this is when two or more molecules combine to formone larger molecule. This reaction is anabolicwhich means that it’s a building reaction. This makes sense because this reactions takes two separate things and puts them together to make one bigger, better thing. A+B = ABDecomposition Reactions: this is when two molecules break apart to form two separate molecules. It’s pretty much the opposite of the synthesis reactions. Since this is the opposite of the synthesis reactions, this is a catabolic reaction. This means that the decomposition reaction is breaking the molecules down. AB = A+BExchange (displacement) Reactions: this reaction is a mix of both a synthesis reaction and a decomposition reaction. Bonds are both made and broken. It breaks up the first molecule and places that part that was broken up with the second molecule in the reaction. AB+C = AC+BOxidation-Reduction Reactions: these are a form of decomposition reactions as well as exchange reactions. They are decomposition reactions because they are breaking apart the oxygen from a molecule. They are exchange reactions because they are exchangingelectrons with another molecule. The oxidation part of the reaction is called oxidation because it loses electrons therefore losing that negative charge making it oxidized. The reduction part is called a reduction because it accepts the electrons therefore making it more negative (a reduction in the charge). More of Chemical Reactions: Can you reverse a Chemical Reaction?Theoretically, yes, this can bedone, however, in biological reactions it is essentially irreversible. Also, you can increase the speed at which a chemical reaction happens. Increasing the temperature, increasing the concentration of the reaction, and lowering the particle size will speed up the chemical reaction. Also, catalysts will speed up reactions. Catalysts will increase the speed of reactions and at the same time the catalysts themselves will not be changed. We also have biologicalcatalystsin our body that are in the form of enzymes. We cannot live without these enzymes.Compounds: There are two classes of compounds called Inorganic Compounds and Organic Compounds. Both are needed for our life function. Inorganic Compounds: these do not contain carbon, and some examples are water, and salts. Water is the most plenteous of the inorganic compounds that we have in our bodies. Water is 60%-80% of our cells, and because of waters properties, it is the most important inorganic compounds. Organic Compounds: these contain carbon, are usually large, and are covalently bonded.Except CO2 and CO, which are considered inorganic. All organic compounds fit into one of these categories: carbohydrates, lipids, proteins, and nucleic acids.Acids and Bases: acids and bases are rated on the pH scale, it is important to remember that the lower the pH number the higher the acidity. The higher the pH number, the higher the concentration of the base. A seven on the pH scale means that it is neither an acid nor a base, it means that it is completely neutral. Something is neutral when the numbers of (H+) and (OH-) isequal.The pH scale goes from zero (the most acidic) to 14 (the most basic). The pH scale is logarithmic and so when you go down the scale, a 5 is 10 times more acidic than a 6.Acids: on the pH scale go from 0-6.99As (H+) increases the acidity increasesAs(OH-) decreases,