2-Basic-Chemistry.pptx

Anatomy & Physiology Basic Chemistry MATTER & ENERGY Matter - anything that occupies space and has mass - may exist as one of three states: Solid: definite shape and volume Liquid: definite volume; shape of container Gaseous: neither a definite shape nor volume Matter may be changed:...

Anatomy & Physiology Basic Chemistry MATTER & ENERGY Matter - anything that occupies space and has mass - may exist as one of three states: Solid: definite shape and volume Liquid: definite volume; shape of container Gaseous: neither a definite shape nor volume Matter may be changed: Physically - Changes do not alter the basic nature of a substance - Examples include changes in the state of matter (solid, liquid, or gas) Chemically Changes alter the chemical composition of a substance  COMPOSITION OF MATTER Elements - fundamental units of matter - 96 percent of the body is made from the four elements: 1. Oxygen (O)—most common; 65% of the body’s mass 2. Carbon (C) 3. Hydrogen (H) 4. Nitrogen (N) Periodic table contains a complete listing of elements © 2018 Pearson Education, Inc. Energy - the ability to do work - has no mass and does not take up space Kinetic energy: energy is doing work Potential energy: energy is inactive or stored  Forms of Energy Chemical energy: stored in chemical bonds of substances Electrical energy: results from movement of charged particles Mechanical energy: energy directly involved in moving matter Radiant energy: travels in waves energy of the electromagnetic spectrum  MOLECULES AND COMPOUNDS Molecule: two or more atoms of the same elements combined chemically Example of a chemical reaction, shown as a chemical equation, resulting in a molecule: H (atom) + H (atom) → H2 (molecule) The reactants are the atoms on the left The product is the molecule on the right, represented by a molecular formula Compound: two or more atoms of different elements combined chemically to form a molecule of a compound Example of a chemical reaction resulting in a compound: 4H + C → CH4 (methane) BIOCHEMISTRY: THE CHEMICAL COMPOSITION OF THE LIVING MATTER Inorganic compounds - Lack carbon - Tend to be small, simple molecules - Include water, salts, and many (not all) acids and bases Organic compounds - Contain carbon - All are large, covalent molecules - Include carbohydrates, lipids, proteins, and nucleic acids INORGANIC COMPOUNDS Water - Most abundant inorganic compound in the body - Accounts for two-thirds of the body’s weight Salts - Ionic compound - Easily dissociate (break apart) into ions in the presence of water - Vital to many body functions INORGANIC COMPOUNDS Acids Electrolytes that dissociate (ionize) in water and release hydrogen ions (H+) Bases Electrolytes that dissociate in water and release hydroxyl ions (OH–) pH pH measures relative concentration of H (and hydroxide) ions in body fluids pH scale runs from 0 to 14 ORGANIC COMPOUNDS Carbohydrates - Contain carbon, hydrogen, and oxygen, include sugars and starches - Classified according to size and solubility in water Monosaccharides—simple sugars and the structural units of the carbohydrate group Disaccharides—two simple sugars joined by dehydration synthesis Polysaccharides—long-branching chains of linked simple sugars Lipids - Most abundant are the triglycerides, phospholipids, and steroids - Contain carbon, hydrogen, and oxygen Carbon and hydrogen outnumber oxygen - Insoluble in water, but soluble in other lipids ORGANIC COMPOUNDS Fatty acid chains of triglycerides Saturated fats: exist as solids at room temperature since molecules pack closely together Unsaturated fats: “Heart healthy” Trans fats: Oils that have been solidified by the addition of hydrogen atoms at double bond sites Increase risk of heart disease Omega-3 fatty acids: Found in cold-water fish and plant sources, including flax, pumpkin, and chia seeds; walnuts and soy foods, appear to decrease risk of heart disease ORGANIC COMPOUNDS Phospholipids - Contain two fatty acids chains rather than three; they are hydrophobic (“water fearing”) - Phosphorus-containing polar “head” carries an electrical charge and is hydrophilic (“water loving”) ORGANIC COMPOUNDS Steroids - Formed of four interlocking rings - Include cholesterol, bile salts, vitamin D, and some hormones - Some cholesterol is ingested from animal products; the liver also makes cholesterol - Cholesterol is the basis for all steroids made in the body ORGANIC COMPOUNDS Proteins - Account for over half of the body’s organic matter - Provide for construction materials for body tissues Play a vital role in cell function Act as enzymes, hormones, and antibodies Contain carbon, oxygen, hydrogen, nitrogen, and sometimes sulfur - Built from building blocks called amino acids ORGANIC COMPOUNDS Enzymes - Act as biological catalysts - Increase the rate of chemical reactions - Bind to substrates at an active site to catalyze reactions - Can be recognized by their –ase suffix Hydrolase Oxidase ORGANIC COMPOUNDS Nucleic Acids - Form genes - Composed of carbon, oxygen, hydrogen, nitrogen, and phosphorus atoms - Largest biological molecules in the body - Two major kinds: DNA RNA Nucleic acids are built from building blocks called nucleotides Nucleotides contain three parts 1. A nitrogenous base A = Adenine G = Guanine C = Cytosine T = Thymine U = Uracil 2. Pentose (five-carbon) sugar 3. A phosphate group ORGANIC COMPOUNDS Deoxyribonucleic acid (DNA) - The genetic material found within the cell’s nucleus - Provides instructions for every protein in the body - Organized by complementary bases to form a double-stranded helix - Contains the sugar deoxyribose and the bases adenine, thymine, cytosine, and guanine - Replicates before cell division ORGANIC COMPOUNDS Ribonucleic acid (RNA) - Carries out DNA’s instructions for protein synthesis - Created from a template of DNA - Organized by complementary bases to form a single-stranded helix - Contains the sugar ribose and the bases adenine, uracil, cytosine, and guanine - Three varieties are messenger, transfer, and ribosomal RNA ORGANIC COMPOUNDS Adenosine triphosphate (ATP) Composed of a nucleotide built from ribose sugar, adenine base, and three phosphate groups Chemical energy used by all cells Energy is released by breaking high-energy phosphate bond ADP (adenosine diphosphate) accumulates as ATP is used for energy ATP is replenished by oxidation of food fuels