Basic Chemistry PDF

Basic Chemistry Energy  Energy - the ability to do work or transfer heat Has no mass and does not take up space Forms of Energy  Chemical - Energy contained in the chemical bonds between the atoms of the substance’s molecules  Mechanical - Energy contained in objects due to their mov...

Basic Chemistry Energy  Energy - the ability to do work or transfer heat Has no mass and does not take up space Forms of Energy  Chemical - Energy contained in the chemical bonds between the atoms of the substance’s molecules  Mechanical - Energy contained in objects due to their movement, position, or deformation  Radiant - Energy carried by an electromagnetic waves  Thermal - Energy contained in a substance due to the movement of its particles  Nuclear - Energy contained in the nucleus of atoms due to the bonds between protons and Matter  Matter - anything that has mass and takes up space  Matter may exist as one of three states Solid Liquid Gas Matter and Energy  Matter may be changed Physically  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 – make up the periodic table  Human body contains 27 elements  13 of those are considered "common"  14 of those are trace elements (present in very small amounts) Composition of Matter  Atoms - building blocks of elements Elements are many of the same atoms together (ex: one hydrogen atom vs a balloon filled with the element helium) Subatomic Particles  Nucleus Protons (p+) are positively charged Neutrons (n0) are uncharged or neutral  Orbiting the nucleus Electrons (e–) are negatively charged Subatomic Particles  Atoms are electrically neutral Number of protons equals numbers of electrons in an atom Positive and negative charges cancel each other out  Ions are atoms that have lost or gained electrons Inert / Non-reactive Elements  Inert elements are those which are non- reactive. They are not part of the human body  (a) Chemically inert elements Outermost energy level (valence shell) complete 8e 2e 2e He Ne Helium (He) Neon (Ne) (2p+; 2n0; 2e–) (10p+; 10n0; 10e–) Reactive Elements  Reactive elements gain, lose, or share electrons to fill outermost shells  become ions which are more stable  Losing an electron means: Fewer electrons (negative) than protons (positive)  net positive charge Called a positive ion or cation  Gaining an electron means: More electrons (negative) than protons (positive) Net negative charge (b) Chemically reactive elements Outermost energy level (valence shell) incomplete 4e 1e 2e H C Hydrogen (H) Carbon (C) (1p+; 0n0; 1e–) (6p+; 6n0; 6e–) 1e 6e 8e 2e 2e O Na Oxygen (O) (8p+; 8n0; 8e–) Sodium (Na) (11p+; 12n0; 11e–) Chemical Reactions  Atoms are united by chemical bonds  Atoms dissociate from other atoms when chemical bonds are broken Atoms  Main types of bonding: 1. Ionic (transfer of electrons) 2. Covalent (sharing of electrons) Chemical Bonds  Ionic bonds – create electrolytes Form when electrons are completely transferred from one atom to another – new atoms are stable Chemical Bonds  Ions Tend to stay close together because opposite charges attract Electrolytes easily dissolve in water to form ions Chemical Bonds  Covalent bonds Atoms become stable through shared electrons Polarity  Covalently bonded molecules Some are non-polar  Electrically neutral as a molecule Some are polar  Have a positive and negative side  Ionicity (+ / - ) of ion, polarity of molecules, and size of molecules affects ability to Types of Chemical Reactions Reversible  Most chemical reactions are reversible  Reversibility is indicated by a double arrow Reactions Body Survival Needs Biochemistry: Essentials for Life  Inorganic compounds Lack carbon Tend to be small, simple molecules Include water, salts, and some acids and bases  Organic compounds Contain carbon All are large, covalently bonded molecules Important Inorganic Compounds  Water - most abundant inorganic compound + cushioning Important Inorganic Compounds  Electrolytes (Salts) Compound composed of cations and anions held together by ionic bonds Dissociate in water, releasing ions to allow for conduction of an electrical current  Ex: NaCl  Ions are vital to many body functions  Muscle contraction  Nerve function  And many more!  Ions in proper proportion are critical to life Important Inorganic Compounds  Acids Release hydrogen ions (H+)  Bases Release hydroxyl ions (OH–) or bind hydrogen ions (H+) pH  Measures relative concentration of hydrogen ions pH = 7 = neutral pH < 7 = acidic (acidosis) pH > 7 = basic (alkalosis) pH in the Blood  Normal pH of blood is 7.35 to 7.45  Outside this range damages cells and tissues by: Breaking chemical bonds Changing shapes of proteins Altering cellular functions Acidosis vs Alkalosis and Acidemia vs Alkalemia  pH < 7.0 - coma  Important Organic Compounds  Carbohydrates Organic molecules containing C, H and O Usually account for less than 1.5 percent total body weight Most important function is as source of energy (ATP) Important Organic Compounds  Lipids Organic molecules containing C, H and O (less O than carbohydrates) Most are insoluble in water 12–18 % of total body weight in men 18–24 % of total body weight in women  Several essential fatty acids for lipid synthesis must be obtained through diet Important Organic Compounds  Proteins - made of amino acids - all contain C, H, O and N May contain small quantities sulfur and phosphorus 20 different amino acids found in the body Typical protein contains 1000+ amino acids  Account for over half of the body’s organic matter Provide for construction materials for body tissues Play a vital role in cell function The four levels of protein structure The four levels of protein structure Proteins  Can be denatured at a body temperature above 43°C or 110°F Irreparable damage to organs and organ systems  2 classes of proteins: 1. Fibrous / structural 2. Globular / functional Proteins 1. Fibrous proteins Also known as structural proteins Appear in body structures Bind structures together and exist in body tissues Stable proteins Examples include collagen and keratin Proteins  Globular proteins Also known as functional proteins Function as antibodies, hormones, or enzymes Can be denatured and no longer perform physiological roles Active sites “fit” and interact chemically with other molecules Important Organic Compounds  Nucleic Acids Provide blueprint of life by storing and transferring information essential to protein synthesis Make DNA and RNA - largest biological molecules in the body Important Organic Compounds  Adenosine triphosphate (ATP) - most common high-energy compound - released by breaking high-energy phosphate bonds Chemical energy used by all cells to power vital functions  Synthesis of proteins, carbohydrates, and lipids  Contraction of muscles  Nerve signal conduction Blood chemistry – typical values Glucose  Glucose is a primary cellular energy source.  Glucose: Normal Range Fasting 3.3-5.8 mmol/L (59-105 mg/dL) Ions  Sodium (Na+) Sodium is the major cation of extracellular fluids. Serum: 135 – 145 mmol/L Ions  Potassium (K+) Major cation of the intracellular fluid. Serum: 3.5-5.0 mmol/L. Ions  Chloride (Cl-) Major anion in the extracellular water space; maintains proper body water distribution, osmotic pressure, and normal anion-cation balance in the extracellular fluid compartment. Serum: 98-106 mmol/L  Chapter 2 Review a. Define an element. b. Explain how cations and anions form. c. Distinguish between the two most common types of chemical bonds (ionic and covalent). d. What is an enzyme? e. Why are enzymes needed in our cells? f. Identify and describe three types of chemical reactions important in human physiology. i. In cells, glucose, a six-carbon molecule, is converted into two three-carbon molecules by a reaction that releases energy. What is the source of the energy? j. Define electrolytes. i. Define pH. j. Explain the differences among an acid, a base, and a salt. k. What is the significance of pH in physiological systems? l. List the three structural classes of carbohydrates, and give an example of each. m. Describe lipids and their major roles in the body. n. Why is cholesterol necessary in the body? o. Describe the basic functions of steroids, phospholipids, and glycolipids. p. Describe proteins. q. How does boiling a protein affect its structural and functional properties? r. Where do cells obtain the energy needed for their vital functions? s. Describe ATP t. Describe nucleic acids.