Modern
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
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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:
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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
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
– 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)
Nitric Acid - HNO3
Nitrous Acid - HNO2
Hypochlorous Acid - HClO
Chlorous Acid - HClO2
Chloric Acid - HClO3
Perchloric Acid - HClO4
Sulfuric Acid - H2SO4
Sulfurous Acid - H2SO3
Phosphoric Acid - H3PO4
Phosphorous Acid - H3PO3
Carbonic Acid - H2CO3
Acetic Acid - HC2H3O2
Oxalic Acid - H2C2O4
Boric Acid - H3BO3
Silicic Acid - H2SiO3
Sodium Hydroxide - NaOH
Potassium Hydroxide - KOH
Ammonium Hydroxide - NH4OH
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
• Bases – the presence of OH (hydroxide ion) in
solution
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