The Chemistry of Life https://www.youtube.com/watch?v=FSyAehMdpyI&list=PL8dPuuaLjXtPHzzYuWy6fYEaX9mQQ8oGr

The Atom Atom – smallest particle of an element

Atoms Composed of 3 subatomic particles: 1. Proton – positively charged particle found within the nucleus 2. Neutron – particle with no charge found within the nucleus 3. Electron – negatively charged particle found outside the nucleus

Elements Element – pure substance made of one type of atom Periodic Table – Organizes elements Atomic Number - # of protons Atomic Mass - # of protons + neutrons Know how to determine protons, neutrons, and electrons in at atom using these numbers https://www.youtube.com/watch?v=dRfrvpVdKGM

Periodic Table

Periodic Table Organizaton There is a repeating pattern (periodicity) Groups/Families – vertical rows share similar characteristics Periods – horizontal rows

Hydrogen

Alkali Metals

Alkaline Earth Metals

Transition Metals

Boron Group

Carbon Group

Nitrogen Group

Oxygen Group

Halogens

Noble Gases

Lanthanides and Actinides

Metals, Nonmetals, and Metalloids

Isotope Isotope – atoms of the same element with a different number of neutrons – therefore a different mass

Radioactive Isotope Radioactive isotope – isotopes with unstable nuclei Give off harmful radiation Used in dating materials; many medical uses

Compounds Compound – a substance that is made of atoms of different elements chemically combined. Water is a compound H2O Properties are different from those of the individual elements. Table salt (NaCl) – which is made of Na and Cl

Compounds

Determining the arrangement of electrons in energy levels: Energy Levels Electrons must be in distinct energy levels Each energy level can hold a different number of electrons 1st Energy Level – 2 electrons 2nd Energy Level – 8 electrons 3rd Energy Level – 18 electrons 4th Energy Level – 32 electrons Electrons fill the lowest energy levels first.

Bohr Models Niels Bohr – developed a model of the atom that showed electrons in distinct energy levels Lowest energy levels must fill first!

Create a Bohr model for the following elements: Helium Lithium Chlorine Neon

Bohr Models

Bohr Models

Chemical Bonds An atom is most stable when its outer most energy level is full or contains 8 electrons Atoms will gain, lose, or share electrons with other atoms to become stable Valence electrons – electrons in the outermost energy level which are involved in bonding.

Bond Types Ionic Bond – electrons are gained or lost Ion – an atom that has gained or lost electrons Covalent Bond – sharing electrons Molecule – a group of atoms held by covalent bonds and have no charge A molecule of water is represented by H2O

Ionic Bond

Covalent Bond

The Water Molecule Water is one of the most important compounds in living organisms. Water serves as a means of transport. Water makes up 70 – 95% of organisms Water is an example of a polar molecule Polar molecule – molecule with an unequal distribution of charge. Has positive and negative ends = dissolve things Hydrogen Bond – weak bond between hydrogen and oxygen

Hydrogen Bond

Solutions and Suspensions Mixture – a combination of substances in which individual substances retain own properties Ex. Mix sand and sugar – they neither change nor combine Solution – a mixture in which one or more substances are distributed evenly in another substance – Ex. Kool-aid mix and water Solute – substance being dissolved – sugar Solvent – being dissolved in – Water is the universal solvent

Solute vs. Solvent

Solution Na+ Cl - Water

Acids and Bases Chemical reactions depend on pH pH is a measure of how acidic or basic a solution is pH scale: 0 – 14 Neutral Compound: 7 Acid: pH below 7 Acid – any substance that forms hydrogen ions in water Base : pH above 7 Base – any substance that forms hydroxide ions in water

Acids and Bases

Carbon Compounds Carbon – a very unique and important element It can share bonds with other carbon atoms or other elements Can form single, double, or triple bonds Can form chains, rings, and large complex molecules

What is the name of carbon based chemistry?

Macromolecules https://www.youtube.com/watch?v=QWf2jcznLsY (Mr. Anderson, 10 min.) Large molecules (polymers) formed by linking many smaller molecules (monomers) Main categories of macromolecules: 1. Carbohydrates 2. Lipids 3. Nucleic Acids 4. Proteins

Carbohydrates Carbohydrates – organic compounds composed of carbon, hydrogen, and oxygen in a 1:2:1 ratio. Main source of energy for almost all living things A. Monosaccharides – simplest type of carbohydrate – glucose and fructose B. Disaccharide – two monosaccharides linked together – sucrose or table sugar C. Polysaccharide – many monosaccharides (starch, cellulose, and glycogen)

Carbohydrates Makes up the cell wall (cellulose) Used for short term energy storage Name usually ends in -ose

Lipids Lipids – fats used to store energy. Insoluble in water (important to membranes) Ex. Cholesterol, fats, steroids, etc.

Lipids Long term energy storage Forms bilayer with phosphate which is found in the cell memebrane (phospholipid bilayer)

Nucleic Acids Contain C, H, O, N, and P Store information – determines traits/directs protein synthesis Made up of monomers called nucleotides - RNA – ribonucleic acids (single stranded) - DNA – deoxyribonucleic acids (double stranded/double helix) Contains nitrogenouse bases: Ex. Adenine, Thymine, Guanine, Cytosine

Nucleotides

Proteins Proteins – contain C, H, O, N. Made of monomers called amino acids which are linked together by polypeptide bonds Found throughout the body, but well known to be a main component of muscles All enzymes are proteins

Proteins

Chemical Reactions Reactants – substances undergoing the reaction. On left side of arrow Products – substances being produced. On right side of arrow Equations – must always be written balanced H2 + O2 H2O

Energy in Reactions Activation energy – needed to get reaction started Metabolism – all the chemical reactions that occur within an organisms

Enzymes Catalyst – any substance that speeds up a chemical reaction without being used up in the process. Lowers the activation energy Enzyme – a protein that acts as a catalyst in a living organism. Changes in temperature or pH can adversely affect enzymes Substrate – substance that is acted on by the enzyme. It binds to enzyme where a new product is formed and released