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’tElements 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’tIonic 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 SolutionsPolarity

Water and SolutionsSolubility 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– Aqueous solutions – when water is the solvent• Virtually ALL living organisms

Acids and Bases• Acid – extra H attaches to water making hydronium

ions (H3O) in water. ( a H – ion for short)

• Bases – the presence of OH (hydroxide ion) in solution

Nitric Acid - HNO3

Nitrous Acid - HNO2

Hypochlorous Acid - HClOChlorous Acid - HClO2

Chloric Acid - HClO3

Perchloric Acid - HClO4

Sulfuric Acid - H2SO4

Sulfurous Acid - H2SO3

Phosphoric Acid - H3PO4

Sodium Hydroxide - NaOHPotassium Hydroxide - KOHAmmonium Hydroxide - NH4OHCalcium 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 - H3PO3

Carbonic Acid - H2CO3

Acetic Acid - HC2H3O2

Oxalic Acid - H2C2O4

Boric Acid - H3BO3

Silicic Acid - H2SiO3

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