Anatomy and Physiology Chapter 2: Basic Chemistry PDF

ANATOMY AND PHYSIOLOGY CHAPTER 2 - THE CHEMICAL BASIS OF LIFE DR. ESTHER FALLER A. THREE MAJOR TYPES OF SUBATOMIC CHAPTER 2.1 - Basic Chemistry...

ANATOMY AND PHYSIOLOGY CHAPTER 2 - THE CHEMICAL BASIS OF LIFE DR. ESTHER FALLER A. THREE MAJOR TYPES OF SUBATOMIC CHAPTER 2.1 - Basic Chemistry PARTICLES 1) Neutrons have no electrical charge OUTLINE 2) Protons have positive charges 3) Electrons have negative charges I. Matter, Mass, and Weight II. Elements and Atoms IV. ELECTRONS AND CHEMICAL BONDING. III. Atomic Structure ❖ The chemical behavior of an atom is A. Three Major Types of Subatomic determined largely by its outermost electrons. Particles ❖ Chemical bonding - occurs when the IV. Electrons and Chemical Bonding outermost electrons are transferred or shared A. Two Major Types of Chemical between atoms. Bonding V. Molecules and Compounds A. TWO MAJOR TYPES OF CHEMICAL BONDING VI. Intermolecular Forces 1) Ionic bonding A. Hydrogen Bonds ❖ An atom is electrically neutral because it has B. Dissociation an equal number of protons and electrons. If an atom loses or gains electrons, the numbers of protons and electrons Chemicals are no longer equal, and a charged ❖ Make up the body’s structures particle called an ion is formed. ❖ The interactions of chemicals with one ❖ Occurs when electrons are transferred another are responsible for the body’s between atoms, creating oppositely charged functions. ions. Chemistry ❖ The scientific discipline concerned with the 2) Covalent Bonding atomic composition and structure of ❖ Forms when atoms share one or more pairs of substances and the reactions they go electrons through. ❖ Can be single or double covalent ❖ Basic knowledge of chemistry is essential ❖ Electrons can be shared unequally in covalent for understanding anatomy and physiology. bonds ❖ Resulting combination of atoms is called a I. MATTER, MASS, AND WEIGHT. molecule ❖ Matter - anything that occupies space and has ❖ Polar covalent bond (polar molecules) - the mass. bond in unequal, asymmetrical sharing of ❖ Mass - the amount of matter in an object. electrons. ❖ Weight - the gravitational force acting on an ❖ Nonpolar covalent bond (nonpolar molecules) object of a given mass. - the bond in equal sharing of electrons between atoms. II. ELEMENTS AND ATOMS. ❖ Element - simplest type of matter having unique chemical properties ❖ Atom - the smallest particle of an element that has the chemical characteristics of said element. About 96% of the body’s weight results from the elements oxygen, carbon, hydrogen, and nitrogen. III. ATOMIC STRUCTURE. ❖ Characteristics of matter result from the structure, organization, and behavior of atoms. ❖ Atoms are composed of subatomic particles, some of which have an electrical charge. 1  ANATOMY AND PHYSIOLOGY CHAPTER 2 - THE CHEMICAL BASIS OF LIFE DR. ESTHER FALLER V. MOLECULES AND COMPOUNDS. I. CLASSIFICATION OF CHEMICAL REACTIONS. ❖ Molecule - two or more atoms chemically 1) Synthesis Reactions combined to form a structure that behaves as ❖ Two or more reactants combine to an independent unit. form a larger, more complex product. ❖ Compound - two or more different types of ❖ Synthesis reactions that occur in the atoms chemically combined. It can be a body are collectively referred to as molecule (covalent compound) or an anabolism. Growth, maintenance, and organized array of ions (ionic compound). repair of the body could not take place without anabolic reactions. VI. INTERMOLECULAR FORCES. ❖ The weak charge attractions that exist between separate molecules, or between ions and molecules. A. HYDROGEN BONDS ❖ Weaker than ionic or covalent bonds ❖ Play an important role in determining the shape of complex molecules ❖ Can occur between different polar parts of a single large molecule to hold the molecule in its normal three-dimensional shape 2) Decomposition Reactions ❖ Reactants are broken down into smaller, less complex products. ❖ Decomposition reactions that occur in the body are collectively called catabolism. B. DISSOCIATION ❖ All the anabolic and catabolic ❖ When ionic compounds dissolve in water, reactions in the body are collectively their ions dissociate or separate from each called metabolism. other ❖ Positively charged ions are attracted to the negative ends of the water molecules ❖ Negatively charged ions are attracted to the positive ends of the water molecules CHAPTER 2.2 - CHEMICAL REACTIONS AND ENERGY OUTLINE 3) Exchange Reactions I. Classification of Chemical Reactions ❖ Combination of synthesis and II. Energy and Chemical Reactions decomposition reactions III. Rate of Chemical Reactions ❖ Symbolic representation of an exchange reaction AB+CD→AC+BD Atoms, ions, molecules, or compounds interact (AgNO3+NaCl→AgCl+NaNO3) either to form or to break chemical bonds. Substances that enter into a chemical reaction are called reactants. Substances that result from the chemical reaction are called the products. 2  ANATOMY AND PHYSIOLOGY CHAPTER 2 - THE CHEMICAL BASIS OF LIFE DR. ESTHER FALLER 4) Reversible Reactions 4) Catalysts ❖ Chemical equations that can proceed from ❖ Increases the rate of a chemical reaction, reactants to products and from products to without itself being permanently changed reactants. or depleted. When the rate of product formation 5) Enzyme is equal to the rate of reactant ❖ A protein molecule that acts as a catalyst. formation, the reaction is said to be at equilibrium. CHAPTER 2.3 - ACIDS AND BASES II. ENERGY AND CHEMICAL REACTIONS. ❖ Potential energy is stored energy that could The body has many molecules and compounds, do work and kinetic energy does work by called acids and bases, that can alter body causing the movement of an object. functions. Energy is: ❖ Acid is a proton donor ❖ Capacity to do work. ❖ Base is a proton acceptor ❖ Exists in chemical bonds as potential energy. ❖ Released in chemical reactions when the products contain less potential energy than OUTLINE the reactants. ❖ Must be added in reactions when the I. The pH Scale products contain more potential energy II. Salts than the reactants. III. Buffers ❖ Can be neither created nor destroyed, but one type of energy can be changed into I. THE pH SCALE. another. ❖ Indicates the H+ concentration of a solution and a scale range from 0 to 14 III. RATE OF CHEMICAL REACTIONS. ❖ Neutral solution has a pH of 7.0 (H+>OH-) ❖ The rate at which a chemical reaction ❖ Acidic solution has a pH < 7.0 (H+>OH-) proceeds is influenced by several factors. ❖ Basic or alkaline solution as Ph > 7.0 This includes: (H+>OH-) 1. How easily the substances react ❖ The pH number and the actual H+ with one another concentration are inversely related, 2. Their concentrations the lower the pH number, the higher 3. The temperature the H+ concentration. 4. The presence of a catalyst ❖ Change of one unit on the pH scale 1) Reactants represents a 10-fold change in the H+ ❖ Differ from one another in their ability to concentration undergo chemical reactions. ❖ Normal pH range for human blood is 7.35 2) Concentration to 7.45 ❖ The greater the concentration of the ❖ If blood pH drops below 7.35, acidosis reactants, the greater the rate at which a results chemical reaction will occur. ❖ If blood pH rises above 7.45, alkalosis As the concentration increases, results the reacting molecules are more likely to come in contact with one another. 3) Temperature ❖ Rate of chemical reactions is partially dependent on temperature. Reactions occur throughout the body at a faster rate when a person has a fever of only a few degrees. The rate of reactions decreases when body temperature drops. 3  ANATOMY AND PHYSIOLOGY CHAPTER 2 - THE CHEMICAL BASIS OF LIFE DR. ESTHER FALLER 2) Carbon Dioxide (CO2) II. SALTS. ❖ Consists of one carbon atom to two oxygen ❖ A compound consisting of a positive ion atoms other than H+ and a negative ion other than ❖ Produced when food molecules (e.g. OH-. glucose), are metabolized within the cells ❖ Formed by the reaction of an acid and of the body. eliminated from the cell as a base. metabolic by-product, transferred to the III. BUFFERS. lungs by the blood, and exhaled during ❖ Chemical that resists changes in pH when respiration. either an acid or a base is added to a II. WATER. solution. ❖ Inorganic molecule ❖ When an acid is added to a buffered ❖ Consists of one atom of oxygen joined by solution, the buffer binds to the H+, polar covalent bonds to two atoms of preventing these ions from causing a hydrogen. decrease in the pH of the solution. ❖ Survival of an organism depends on its A. IMPORTANT ROLES OF WATER IN HUMANS AND ability to maintain homeostasis by keeping ALL LIVING ORGANISMS body fluid pH within a narrow range 1. Stabilizing body temperature 2. Providing protection 3. Facilitating chemical reactions CHAPTER 2.4 - INORGANIC MOLECULES 4. Transporting substances OUTLINE CHAPTER 2.5 - ORGANIC MOLECULES I. Oxygen and Carbon Dioxide II. Water OUTLINE A. Important Roles of Water in Humans and All Living Organisms IV. Organic Molecules A. 2 Mechanisms That Allow the Formation of a Variety of Molecules ❖ It was believed that inorganic substances came B. 4 Majors Groups of Organic from non-living sources and that organic Molecules Essential to Living substances were extracted from living Organisms organisms. V. Carbohydrates ❖ As chemistry developed, it became apparent VI. Lipids that the body also contains inorganic VII. Proteins substances and that organic substances can be VIII. Nucleic Acids: DNA & RNA manufactured in the laboratory. I. ORGANIC MOLECULES. ❖ Inorganic chemistry deals with those ❖ Carbon atoms bound together by covalent substances that do not contain carbon. bonds constitute the “framework” of many Inorganic substances play many vital large molecules. roles in human anatomy and A. 2 MECHANISMS THAT ALLOW THE FORMATION physiology. OF A VARIETY OF MOLECULES ❖ Organic chemistry is the study of 1. Variation in the length of the carbon chains carbon-containing substances 2. Combination of the atoms bound to the carbon framework I. OXYGEN AND CARBON DIOXIDE. 1) Oxygen (O2) B. 4 MAJOR GROUPS OF ORGANIC MOLECULES ❖ Small, nonpolar, inorganic molecule ESSENTIAL TO LIVING ORGANISMS ❖ Consists of two oxygen atoms bound 1. Carbohydrates together by a double covalent bond. 2. Lipids ❖ 21% of the gas in the atmosphere; essential 3. Proteins for most living organisms. 4. Nucleic Acids. 4  ANATOMY AND PHYSIOLOGY CHAPTER 2 - THE CHEMICAL BASIS OF LIFE DR. ESTHER FALLER II. CARBOHYDRATES. d) more covalent bonds between carbon ❖ Composed of carbon, hydrogen, and oxygen atoms.(e.g. safflower, sunflower, corn, atoms. and fish oils) ❖ Smallest carbohydrates are B. PHOSPHOLIPIDS monosaccharides or simple sugars. ❖ Important structural components of cell Disaccharides - formed when two membranes monosaccharides are joined by a covalent bond. ❖ Polar (hydrophilic) at the end of the Polysaccharides - consist of many molecule to which the phosphate is monosaccharides bound in long bound/contained and nonpolar chains. (hydrophobic) at the other end which consists of two fatty acid chains. ❖ The phosphate head of the phospholipid is said to be hydrophilic, or water-soluble. ❖ The nonpolar end of a phospholipid is repelled by water and is said to be hydrophobic, or lipid-soluble. B. EICOSANOIDS ❖ Group of important chemicals derived from fatty acids ❖ important regulatory molecules made in III. LIPIDS. most cells ❖ Substances that dissolve in nonpolar ❖ Has a role in the response of tissues to solvents (alcohol or acetone), but not in injuries polar solvents (water) ❖ One example of eicosanoids is ❖ Composed mainly of carbon, hydrogen, and Prostaglandins oxygen other elements, such as phosphorus C. STEROIDS and nitrogen, are minor components ❖ Composed of carbon atoms bound together of some lipids into four ring-like structures ❖ Contain a lower proportion of oxygen to ❖ Cholesterol is an important steroid carbon than do carbohydrates because other steroid molecules are ❖ EX: fats, phospholipids, eicosanoids, and synthesized from it steroids are examples IV. PROTEINS. A. FATS ❖ Contain carbon, hydrogen, oxygen, and ❖ Important energy-storage molecules nitrogen, and most have some sulfur ❖ Pad and insulate the body ❖ Triglycerides are the most common type of A. AMINO ACIDS fat molecules The building blocks of proteins are ❖ Fatty acids differ from one another which are organic acids according to the length and degree of contain an amine group (–NH2) and saturation of their carbon chains a carboxyl group 1) Saturated Fats - contains only single covalent bonds between the carbon atoms 2) Unsaturated Fats - If it has one or more double covalent bonds a) Monounsaturated Fats - have one double covalent bond between carbon atoms. (e.g. olive, peanut oil) b) Polyunsaturated Fats - have two or c) 5  ANATOMY AND PHYSIOLOGY CHAPTER 2 - THE CHEMICAL BASIS OF LIFE DR. ESTHER FALLER ❖ Consists of adenosine (the sugar ribose 20 BASIC TYPES OF AMINO ACIDS with the organic base adenine) and three phosphate groups ❖ 12 of them can be synthesized but the ❖ Often called the energy currency of cells remaining 8 so-called essential amino acids because it is capable of both storing and must be obtained in the diet providing energy ❖ Important functions include regulation of the rate of chemical reactions and provides the framework for many of the body’s tissues B. ENZYMES ❖ Protein catalyst ❖ increases the rate at which a chemical reaction proceeds without the enzyme being permanently changed V. NUCLEIC ACIDS: DNA AND RNA. ❖ Nucleic acids - large molecules composed of carbon, hydrogen, oxygen, nitrogen, and phosphorus ❖ Both DNA and RNA consist of basic building blocks called nucleotides ❖ Each nucleotide is composed of a sugar (monosaccharide) to which a nitrogenous organic base and a phosphate group are attached ❖ Sugar is deoxyribose for DNA, ribose for RNA ORGANIC BASES ARE: 1. Single-ringed molecules: thymine, cytosine, and uracil 2. Double-ringed molecules: adenine and guanine A. DEOXYRIBOSE NUCLEIC ACID (DNA) ❖ Genetic material of cells ❖ Copies of DNA are transferred from one generation of cells to the next ❖ Contains the information that determines the structure of proteins B. RIBONUCLEIC ACID (RNA) ❖ Structurally related to DNA ❖ Three types of RNA also play important roles in gene expression or protein synthesis Adenosine Triphosphate ❖ Important organic molecule found in all living organisms 6