THE CHEMISTRY OF LIFE

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THE CHEMISTRY OF LIFE
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2-1 THE NATURE OF MATTER

• LIVING THINGS ARE MADE FROM CHEMICAL COMPOUNDS.
• ATOM BASIC UNIT OF MATTER
• -ATOMS ARE MADE OF SMALLER PARTICLES CALLED
  SUBATOMIC PARTICLES

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SUBATOMIC PARTICLES

• PROTONS POSITIVELY CHARGED PARTICLES
• NEUTRONS HAVE NO CHARGE
• PROTONS AND NEUTRONS TOGETHER MAKE UP THE MASS OF
  THE ATOM
• ELECTRONS HAVE A NEGATIVE CHARGE

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MODEL SHOWING SUBATOMIC PARTICLES
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ELEMENTS AND ISOTOPES

• ELEMENT A PURE SUBSTANCE THAT CONSISTS OF JUST
  ONE KIND OF ATOM
• -EXAMPLES HYDROGEN H
• SODIUM Na
• MAGNESIUM - Mg

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An Element in the Periodic Table
Section 2-1
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C
Carbon
12.011
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• ISOTOPES ATOMS OF THE SAME ELEMENT WITH
  DIFFERENT OF NEUTRONS
• - EXAMPLE CARBON 12, 13, 14
• - ISOTOPES HAVE THE SAME OF e-
• SO THEY HAVE THE SAME CHEMICAL PROPERTIES

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• RADIOACTIVE ISOTOPES HAVE UNSTABLE NUCLEI AND
  BREAK DOWN AT A CONSTANT RATE OVER TIME
• - USES DETERMINE AGE OF ROCKS AND FOSSILS,
  TREAT CANCER, KILL BACTERIA

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CHEMICAL COMPOUNDS

• COMPOUND SUBSTANCE FORMED BY CHEMICALLY
  COMBINING TWO OR MORE ELEMENTS IN DEFINITE
  PROPORTIONS
• -EXAMPLES WATER H2O, SALT NaCl, CARBON
  DIOXIDE CO2

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CHEMICAL BONDS

• TWO MAIN TYPES OF BONDS
• IONIC TRANSFER OF e-
• -EX. SEE PAGE 38 NaCl
• COVALENT SHARING OF e-
• -EX. SEE PAGE 38 H2O
• -MOLECULE WHEN ATOMS JOIN TOGETHER BY COVALENT
  BONDS

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2-2 PROPERTIES OF WATER

• WATER IS A POLAR MOLECULE. THAT IS, IT HAS AN
  UNEVEN DISTRIBUTION OF e- BETWEEN THE OXYGEN AND
  HYDROGEN ATOMS
• WATER IS COHESIVE. ATTRACTION BETWEEN MOLECULES
  OF SAME SUB.
• WATER IS ADHESIVE. ATTRACTION BETWEEN MOLECULES
  OF DIFFERENT SUBSTANCES

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SOLUTIONS AND SUSPENSIONS

• MIXTURE A MATERIAL COMPOSED OF TWO OR MORE
  ELEMENTS OR COMPOUNDS PHYSICALLY MIXED
• -EX AIR, SAND AND WATER, SALT AND WATER

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SOLUTIONS

• SOLUTION MIXTURE WHERE PARTICLES ARE EVENLY
  DISTRIBUTED
• TWO PARTS
• -SOLUTE SUB. THAT IS
• DISSOLVED
• -SOLVENT DOES THE
• DISSOLVING

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SUSPENSION

• SUSPENSION MIXTURE OF WATER AND SUBSTANCES THAT
  DO NOT DISSOLVE
• -EX. SAND AND WATER, BLOOD

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ACIDS, BASES, AND pH

• ACID ANY COMPOUND THAT FORMS H IN SOLUTION
• BASE COMPOUNDS THAT PRODUCE HYDROXIDE (OH-) IN
  SOLUTION

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pH SCALE
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2-3 CARBON COMPOUNDS

• Carbons structure HAS FOUR VALENCE ELECTRONS
• A carbon atom can bond to other carbon atoms TO
  FORM CHAINS OR RINGS

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MACROMOLECULES

• Macromolecules mean GIANT MOLECULES
• -monomers SMALL UNITS
• -polymers LARGE UNITS
• Four groups of organic compounds found in living
  things CARBOHYDRATES, LIPIDS, NUCLEIC ACIDS,
  PROTEINS

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CARBOHYDRATES

• Made up of CARBON, HYDROGEN, OXYGEN
• Gives us ENERGY and used for STRUCTURAL PURPOSES
• Monomer - SUGARS
• -simple sugars are called MONOSACCHARIDES
• -some examples are GLUCOSE, GALACTOSE, FRUCTOSE

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Figure 2-13 A Starch
Section 2-3
Starch
Glucose
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CARBOHYDRATES

• Polymer - STARCHES
• -monosaccharides join together to form
  POLYSACCHARIDES
• -some examples are
• GLYCOGEN - animal starch
• STARCH - what plants use for energy
• CELLULOSE - give plants strength

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LIPIDS

• Lipids are made mostly from CARBON, HYDROGEN, AND
  OXYGEN
• -some examples are FATS, OILS, AND WAXES
• -saturated NO DOUBLE BONDS
• BUTTER
• -unsaturated HAS DOUBLE OR TRIPLE BONDS -
  OLIVE OIL

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LIPIDS

• Function of lipids STORE ENERGY, INSULATION,
  MAKE UP MEMBRANES
• -another example - STEROIDS
• which function as CHEMICAL MESSENGERS

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NUCLEIC ACIDS

• Nucleic acids contain CARBON, HYDROGEN, OXYGEN,
  NITROGEN, AND PHOSPHORUS
• -building blocks are called NUCLEOTIDES
• -3 parts
• 5-CARBON SUGAR
• PHOSPHATE GROUP
• NITROGEN BASE

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NUCLEIC ACIDS

• Function of nucleic acids STORE AND TRANSMIT
  HEREDITARY OR GENETIC INFORMATION
• Two types DNA AND RNA

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PROTEINS

• Proteins contain CARBON, HYDROGEN, OXYGEN,
  NITROGEN
• -building blocks AMINO ACIDS
• - 20 different kinds

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PROTEINS

• Function of proteins
• CONTROL RATE OF CHEMICAL REACTION
• REGULATE CELL PROCESSES
• FORM BONE AND MUSCLE
• TRANSPORT SUBSTNACES
• FIGHT DISEASE

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2-4 CHEMICAL REACTIONS AND ENZYMES

• Chemical reaction PROCESS THAT CHANGES ONE SET
  OF CHEMICALS INTO ANOTHER
• -two parts
• REACTANTS - enter reaction
• PRODUCTS - produced by reaction

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CHEMICAL REACTIONS

• AN EXAMPLE OF A CHEMICAL REACTION
• CO2 H2O --? H2CO3
• CARBON DIOXIDE WATER YIELDS CARBONIC ACID

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ENZYMES

• CATALYST SUBSTANCE THAT SPEEDS UP A CHEMICAL
  REACTION
• -enzymes are BIOLOGICAL CATALYSTS
• -enzymes SPEED UP CHEMICAL REACTIONS IN CELLS

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ENZYME ACTION

• For a chemical reaction to take place, THE
  REACTANTS MUST COLLIDE WITH EACH OTHER TO BREAK
  THE BONDS
• -SUBSTRATES are what the enzyme breaks down or
  builds up
• -the site where an enzyme and substrate meet
  is called the ACTIVE SITE

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