Basic Chemistry in the Human Body matter has volume and mass Solid, liquids, gases – all found in the body Can undergo physical and chemical change Matter energy is massless and affects matter Kinetic and potential energy Ability to do work or put matter in motion Energy

Forms of Energy Chemical: energy stored in chemical bonds body uses chemical energy in foods Electrical: energy resulting from movement of charged particles (electrons) body generates electrical current across charged particles Mechanical: energy involved in moving matter muscles shorten pulling on bones causing limbs to move Radiant: energy travelling in waves light energy stimulates eyes, UV rays stimulate body to make vitamin D

Energy Conversions ATP: stores chemical energy Can be converted to other forms Conversions are inefficient Some energy lost as heat Heat lost in body makes us warm-blooded animals

Common Elements in the Body 65% of body mass In organic and inorganic molecules Needed to oxidize glucose during ATP production Oxygen 18.5% of body mass Primary component of all organic molecules such as carbohydrates, lipids, proteins, and nucleic acids Carbon 9.5% of body mass In most organic molecules Influences pH of body fluids Hydrogen 3.2% of body mass Component of proteins and nucleic acids Nitrogen Calcium: in bones and teeth, muscle contraction, neural transmission, & blood clots Phosphorus: in bones and teeth, nucleic acids, and proteins, needed for ATP Potassium: needed for conduction of nerve impulses and muscle contraction Other Elements

A Little Chemistry Review Covalent Bonding Sharing of electrons between atoms Ionic Bonding Transfer of electrons from one atom to another Hydrogen Bonding Weak bonds between H-O or H-N Important for surface tension in H2O and 3D shape of proteins Chemical Reactions: Synthesis reactions Decomposition reactions Exchange reactions Single and double replacement

Two Types of Compounds Organic Compounds Inorganic Compounds Contain carbon Carbohydrates Lipids Proteins Nucleic Acids Inorganic Compounds Lack carbon and tend to be simpler & smaller Water Salts Acids Bases

Water & its functions Inorganic Compounds High heat capacity Is Polar Most abundant inorganic compound in the body Approx. 2/3 of entire body weight High heat capacity Absorbs and releases lots of heat without changing temperature drastically This helps prevent sudden changes in body temperature Is Polar Polarity makes it an excellent solvent allows water to act as transport medium within the body Chemical Reactivity Water is important to many chemical reactions within the body Cushioning Acts as a protective cushion in the body Cerebrospinal fluid Amniotic fluid

Inorganic Compounds Cont. Salts & their functions Calcium and phosphorus salts are most common in the body Salts are vital to body function Sodium and potassium ions from salts are necessary nerve impulses Iron needed to form hemoglobin in the blood Salts are electrolytes Conduct electrical current in solution When electrolytes out of balance the body struggles to function properly

Inorganic Compounds Cont. Bases Acids Substance that can release H+ ions (proton donors) Have a sour taste Proton acceptors Hydroxides and bicarbonates are common in the body Have a bitter taste Acids and Bases react with each other to form water and a salt – neutralization Cells are very sensitive to slight pH changes Kidneys, lungs, and buffers are important to maintaining acid-base balance Ex. Normal blood pH 7.35-7.45, if dips too much hemoglobin unable to carry enough oxygen and can be fatal (condition known as acidosis)

Organic Compounds Carbohydrates Includes sugars and starches Contain C, H, O usually following CnH2nOn ratio Provide easy to use source of food energy for body’s cells Energy released from breakdown of carbs can be stored in ATP or as fat Monosaccharides Simple sugars with 3-7 carbons Includes glucose, fructose, galactose, ribose, & deoxyribose Disaccharides Made of 2 simple sugars Includes sucrose, lactose, & maltose Must be broken down by hydrolysis before being absorbed into the body Polysaccharides Made of long chains of simple sugars Includes starches and glycogen

Organic Compounds cont. Lipids Contain C, H, O with C & H far more numerous than O (ex. C57H110O6 ) Found in meat, egg yolk, milk products, and oils Insoluble in water Neutral Fats (triglycerides) made of 3 fatty acids attached to glycerol Found in fat deposits around body Protect and insulate body organs Major source of stored energy Phospholipids Similar to neutral fats but contain phosphorous Found in cell membranes allowing membrane to be selectively permeable Help form white matter of brain and nervous tissue Steroids Cholesterol In cell membranes, used to make other steroids and hormones Bile salts From liver, needed in digestion Vitamin D Normal bone growth Sex hormones Estrogen/progesterone Testosterone

Organic Compounds cont. Proteins Contain C, H, O, N, and sometimes S Made of building blocks called amino acids Classified as fibrous or globular Fibrous Proteins Important for binding structures together and giving strength Ex. Collagen in bones, cartilage, and tendons Ex. Keratin in hair, nails, and skin Globular Proteins Also called functional proteins Antibodies aka: immunoglobulins Function in immune response to protect body from invading substances Hormones Regulate growth and development Ex. Growth hormone, insulin, nerve growth factor Transport proteins Ex. Hemoglobin in blood transports oxygen Enzymes Act as catalysts to almost all reactions within the body

Organic Compounds cont. Nucleic Acids Make up genes in chromosomes Direct growth and development by dictating the structure of proteins Contain C, H, O, N, P Made up of nucleotides containing a nitrogenous base, a pentose sugar, and a phosphate group Nitrogenous bases include adenine, guanine, cytosine, thymine, and uracil Deoxyribonucleic Acid (DNA) Genetic material in cell nucleus 2 major functions Replicates itself before cell division to ensure all genetic information in all cells is identical Provides instructions for building every protein in the body Double strand of nucleotides known as a double helix Contains deoxyribose sugar Ribonucleic Acid (RNA) Found outside the nucleus “molecular slave” of DNA Carries out protein synthesis as ordered by DNA Single strand of nucleotides Messenger RNA Carries DNA’s instructions from nucleus to ribosomes Ribosomal RNA Oversees binding together of amino acids in ribosomes during protein synthesis Transfer RNA Brings amino acids to ribosomes

Importance of ATP Adenosine Triphosphate Provides form of energy usable by all cells Chemical energy in glucose cannot be used directly by cells Energy released from glucose is stored in bonds of ATP Energy that is usable by all cells is released when a phosphate bond in ATP is broken Adenosine Triphosphate