The Chemistry of Life Biochemistry =Branch of science that deals with the chemical composition (makeup) and processes of living things

I. Atoms The basic unit of matter (Matter = anything that has mass and takes up space) There are three subatomic particles that are combined to make each atom. * Proton (+) * Neutron (o) * Electron (-) move around nucleus in electron cloud Nucleus (+) Energy Levels 1st = 2 2nd = 8 3rd = 18

C. Isotopes – Atoms of the same element with different number of neutrons 1. Identified by mass number (atomic mass) 2. Ex.: Carbon-12; Carbon-13; Carbon-14

II. Elements An element is a substance that contains one type of atom We can find information about all known elements in the Periodic Table of Elements

Element Key Atomic Number (+), (-) Chemical Symbol Element Name Atomic Mass/ Mass Number (+ ; o) (protons plus neutrons) Atomic Number = number of protons in nucleus All atoms of the same element have same atomic number This number also equals number of electrons in electron cloud Atomic Mass = average of all the isotopes of that element Mass Number = number of protons and neutrons that make up atom nucleus 1 H Hydrogen 1.0079

Equations to know: At. Mass = p + n p = protons At. No. = p = e n = neutrons e = p e = electrons All substances are made up of elements On Earth 90 elements occur naturally 25 elements are essential to living things * Carbon ( C) * Hydrogen (H) * Oxygen (O) * Nitrogen (N) 96 % of human body

III. Combining Atoms When two or more atoms are combined a molecule is formed (O₂) When two or more atoms of different elements combine a compound is formed (CO₂)

ALL COMPOUNDS ARE MOLECULES, BUT NOT ALL MOLECULES ARE COMPOUNDS!!!!!! Be able to explain this statement.

We can describe the composition of compounds by using a chemical formula Ex: H₂O (2 atoms of hydrogen, 1 atom of oxygen) C₆H₁₂O₆ (6 carbon, 12 hydrogen, 6 oxygen)

Chemical properties = characteristics The chemical properties of each compound are different from each of the elements that form it. Chemical properties = characteristics Ex: Sodium (Na) – silver metal, soft, reacts violently with water Chlorine (Cl) – poisonous, green gas --------------------------------------------------------------------- Sodium Chloride (NaCl) or table salt White solid, dissolves easily in water, essential for survival of living things

IV. Chemical Bonds Bonds : a force that holds atoms together Covalent Bonds Forms when atoms share electrons Share 2 = single bond Share 4 = double bond Share 6 = triple bond Ex: water

a. Formed when atoms lose or gain electrons Ionic Bonds a. Formed when atoms lose or gain electrons b. Creates electrically charged atoms called ions (different number of protons/electrons) * if atom loses electron = + ion * if atom gains electron = - ion c. Ions with opposite charges are attracted to each other.

d. Ex: NaCl

Hydrogen Bonds a. Form when the positive end of one molecules is attracted to the negative end of another molecules b. Form without the interaction of electrons c. Responsible for the cohesion of water *allows raindrops to form or water to bead d. Easily broken

V. Mixtures and Compounds Mixture: two or more substances that are not chemically combined Heterogeneous: components not evenly mixed; all components keep their own identity Example: sand, salad, soup Homogeneous: components are evenly mixed; cannot see each component; also called solution Example: kool-aid, air

1. Solute: substance being dissolved C. Suspensions Components of a mixture can be separated by physical means, while components of a compound must be separated by chemical means. B. Parts of a Solution 1. Solute: substance being dissolved 2. Solvent: substance doing the dissolving C. Suspensions 1. form when some materials do not dissolve 2. ex: blood – mostly H₂O, dissolved compounds, cells, and misc. particles

VI. Acids/Bases/pH Acids – a solution with a high concentration of Hydrogen ions (H+) B. Bases – a solution with a high concentration of hydroxide ions (OH-) C. pH – means potential for hydrogen

pH Scale: a measurement system used to indicate pH Scale: a measurement system used to indicate the concentration of H+ ions ranges from 0 - 14 0.1 – 6.9 = acid (pop, juice, coffee) 7. 0 = neutral (pure water) 7.1 – 14 = base (blood, soap, some cleaning products) pH can determine what type of organisms can live in an environment or what types of chemical reactions can take place 7.0 pure water

2 H₂ + O₂ → 2 H₂O Balancing Equations Steps to Solve Equation 1. write down elements on reactants side 2. write down elements on product side 3. write number of atoms for each element on each side 4. Begin adding coefficients to balance equation

Practice Problems ____ N₂ + ____ H₂ → ____ NH₃ ____ Cu₂O + ____ C → ____ Cu + ____CO₂ ____ Mg + ____ O₂ → ____MgO ____CH₄ + ____ O₂ → ____CO₂ + ____ H₂O

5. ___ Zn + ____ CrCl₃ → ____CrCl₂ + ____ZnCl₂ 6 5. ___ Zn + ____ CrCl₃ → ____CrCl₂ + ____ZnCl₂ 6. ___ CO₂ + ___ H₂O → ____C₆H₁₂O₆ + ____ O₂ 7. ____C₂ + ____H₂ + ____OH → ____C₃H₇OH 8. ____C₃ + ____H₂O → ____C₉H₈O₄

9. ____O₂ + ____Cl₂S₃ → ____Cl₂O₄ + ____ SO₂ 10 9. ____O₂ + ____Cl₂S₃ → ____Cl₂O₄ + ____ SO₂ 10. ____N₂ + ____H₂ + ____Cl₃ → ____NH₄Cl

ORGANIC CHEMISTRY Organic chemistry is the study of compounds that contain bonds between carbon atoms Carbon atoms have 4 valence electrons; therefore, each electron can join with electrons from another atom to form strong covalent bonds Carbon can bond with: * Hydrogen (H) * Phosphorus (P) * Oxygen (O) * Carbon (C) * Nitrogen (N) * Sulfur (S)

C. Carbon can form chains of unlimited lengths

II. Organic Compounds Found in All Living Things Carbohydrates Lipids Proteins Nucleic acids

A. Carbohydrates Made up of C, H, and O in a 1 : 2 : 1 ratio Uses Energy (quick) Structural building blocks (cellulose – plant cell walls) Sugars and Starches Monosaccharides (one) Disaccharides (two) Polysaccharides (many)

Monosaccharides Simple sugar Chemical formula: C₆H₁₂O₆ Ex: Glucose, Fructose, and Galactose are 3 isomers of a monosaccharide = molecules with same chemical formula but different structure

Disaccharides A two-sugar molecule When 2 carbohydrate monomers are joined, a dehydration synthesis(removal of H₂O) takes place to form a disaccharide. Chemical formula: C₁₂H₂₂O₁₁ Ex: glucose + galactose → Lactose When disaccharides are used for energy, they are digested by enzymes that break them up into monosaccharides which are metabolized in the process of cellular respiration

Hydrolysis Reaction glucose + galactose → Lactose (C₆H₁₂O₆) + (C₆H₁₂O₆) - (H₂O) = C₁₂H₂₂O₁₁ Monomer = a single unit/molecule To digest lactose (sugar in dairy), you need lactase enzyme Lactose intolerant people can’t produce lactase

Polysaccharides Large macromolecules or polymers that can consist of hundreds or thousands of monomers (C₆H₁₀O₅)n Starches (plant: corn & wheat) a. Amylase (enzyme) breaks it down into monomers which are absorbed into the bloodstream to be used by the cells. Glycogen (animal starches) a. Stored in the liver and muscles when there is excess monosaccharides Cellulose a. Can not be digested = roughage

B. Lipids Made up mostly of C and H with some O Uses: Energy – 2x the amount of chemical energy per gram compared to carbohydrates Making biological membranes Ex: plasma membrane in cells Water proof coverings in plants Physical & thermal insulation to animals

Lipids are generally insoluable in water Formed when a glycerol molecule (C₃H₅O₃) joins a fatty acid Saturated fats form when each carbon atom in the fatty acid chain is joined to another carbon atom by a single covalent bond Solid at room temperature Ex: butter

Unsaturated fats form when there is a least one carbon-carbon double bond liquid at room temperature Olive oil c. Polyunsaturated fats form when there are two or more carbon-carbon double bonds Corn, sesame & peanut oil

Steroids are lipids whose C, H, and O atoms are arranged in rings Estrogen, Androgen, Cholesterol

C. Proteins 1. Made up of C, H, O, and N Uses: a. Regulate cell processes and control reaction rates b. Make up bulk of all solid material in the body (muscle, bone, skin, hair) c. Transport substances in and out of cell

Proteins are polymers of amino acids a. Amino acids are compounds with an amino group (NH₂) at one end and a carboxyl group (COOH) at the other. b. There are 20 different amino acides c. Amino acids are joined together by peptides bonds to form a dipeptide or a polypeptide molecule

Enzymes are proteins that are formed during the process of protein synthesis Enzymes are biological catalysts that control the rate of chemical reactions. Each type of enzyme catalyzes only one type of reaction. Names of enzymes usually end in –ase and are named for the reaction they catalyze. Example: lactase → lactose protease → protein

D. Nucleic Acids Made up of C, H, O, N, and P Uses: a. Store and transmit genetic information b. Make proteins Made up of nucleotides 5 – Carbon sugar Phosphate group Nitrogenous base 4. Example: DNA and RNA