Chapter 2 - Chemistry of Life

Composition of Matter Matter – anything the occupies space and has mass

Composition of Matter Mass – quantity of matter an object has – Weight – gravity acting on mass

Composition of Matter, con’t Elements and Atoms Elements – substances that cannot be broken down chemically into simpler matter – Explained by Periodic table Chemical symbols Atomic number Mass number ATOMS – simplest form of matter – Electron (-) » Orbitals – probable location – Nucleus » Neutrons » Protons (+) Isotopes – same # protons, different number of neutrons

Compounds Definition : 2 or moreDIFFERENT elements chemically combined Held together by chemical bonds – Covalent bond- electrons are shared (water) Becomes a molecule – simplest substance that retains all of the properties of that substance

Compounds, con’t Ionic bond – atoms (ions) attracted to each other due to opposite charges Becomes an ionic substance (salts)

Energy Energy – the ability to do work – Types found in living organisms: Chemical energy Thermal energy Electrical energy Mechanical energy

States of Matter Energy changes cause change of states of matter – Solids – Liquids – gases

Energy and Chemical Reactions Chemical Reactions – one substance changes into another substance – Energy is either GAINED or GIVEN OFF during a reaction – Reactants on left, Products on Right of yield sign – Metabolism – a total of all chemical reactions found in an organism

Energy and Chemical Reactions, con’t Activation Energy –amount of energy necessary to START a reaction Catalyst – speed up ANY reaction – Enzyme – a catalyst in living organisms

Energy and Chemical Reactions, con’t Oxidation- Reduction Reactions (REDOX) – OILRIG – oxidation is loss, Reduction is gain – of electrons

Water and Solutions Polarity Polarity

Water and Solutions Solubility of Water Like dissolves like – Polar dissolves polar

Hydrogen Bonding Bond between H and another atom – due to charge

Cohesion and Adhesion Cohesion due to H bond – Holds molecules of a SINGLE substance together Adhesion- attractive force between two different substances – Capillary action (fluid rises) (meniscus) cohesion Adhesion

Solutions Solution – solutes are evenly distributed – Solutes – dissolve in a solvent – Universal solvent – water – Concentration – how much solvent is dissolved in the solute – Saturated solution – one that can not hold ANY more solvent at room temperature Saturated solution – Aqueous solutions – when water is the solvent Virtually ALL living organisms

AcidsAcids and Bases Acid – extra H attaches to water making hydronium ions (H 3 O) in water. ( a H – ion for short) Bases – the presence of OH (hydroxide ion) in solution Nitric Acid - HNO 3 Nitrous Acid - HNO 2 Hypochlorous Acid - HClO Chlorous Acid - HClO 2 Chloric Acid - HClO 3 Perchloric Acid - HClO 4 Sulfuric Acid - H 2 SO 4 Sulfurous Acid - H 2 SO 3 Phosphoric Acid - H 3 PO 4 Sodium Hydroxide - NaOH Potassium Hydroxide - KOH Ammonium Hydroxide - NH 4 OH Calcium Hydroxide - Ca(OH) 2 Magnesium Hydroxide - Mg(OH) 2 Barium Hydroxide - Ba(OH) 2 Aluminum Hydroxide - Al(OH) 3 Ferrous Hydroxide or Iron (II) Hydroxide - Fe(OH) 2 Ferric Hydroxide or Iron (III) Hydroxide - Fe(OH) 3 Zinc Hydroxide - Zn(OH) 2 Lithium Hydroxide - LiOH Phosphorous Acid - H 3 PO 3 Carbonic Acid - H 2 CO 3 Acetic Acid - HC 2 H 3 O 2 Oxalic Acid - H 2 C 2 O 4 Boric Acid - H 3 BO 3 Silicic Acid - H 2 SiO 3

pH pH – a measure of acid and base pH in living organisms

Buffers Natural substances that neutralize small amounts of acids and bases in living organisms Natural substances that neutralize