THE CHEMICAL BASIS OF LIFE
THE CHEMICAL BASIS OF LIFE
• EMERGENT PROPERTIES
– HYDROGEN AND OXYGEN INDIVIDUALLY VERSUS
H2O
THE CHEMICAL BASIS OF LIFE
• LIFE IS MADE UP OF 25 ELEMENTS
– WHAT IS AN ELEMENT?
– 92 NATURALLY OCCURING ELEMENTS
• 25 ARE NECESSARY FOR LIFE
• WHAT ARE THE MAJOR ELEMENTS?
• WHAT ARE THE TRACE ELEMENTS?
THE CHEMICAL BASIS OF LIFE
• TRACE DOESN’T MEAN USELESS!!!
• SAY HI TO A
“GOITER”
THE CHEMICAL BASIS OF LIFE
• ELEMENTS CAN
COMBINE TO
FORM
COMPOUNDS
• HOW AND WHY
DOES THIS
OCCUR??
THE CHEMICAL BASIS OF LIFE
• ELEMENTS CAN COMBINE TO FORM
COMPOUNDS
– WHAT IS AN ATOM?
• SUBATOMIC PARTICLES
– PROTONS
– NEUTRONS
– ELECTRONS
– WHAT DOES AN ATOM LOOK LIKE?
THE CHEMICAL BASIS OF LIFE
THE CHEMICAL BASIS OF LIFE
• WHAT GIVES DIFFERENT ELEMENTS THEIR
DIFFERENT PROPERTIES?
– ATOMIC NUMBER
– ATOMIC MASS
• WHAT ARE ISOTOPES?
THE CHEMICAL BASIS OF LIFE
• RADIOACTIVE
ISOTOPES CAN
BE USEFUL IN
RESEARCH
AND MEDICAL
DIAGNOSIS
THE CHEMICAL BASIS OF LIFE
• ELECTRON ARRANGEMENTS DETERMINE THE
CHEMICAL PROPERTIES OF AN ATOM
– ELECTRON SHELLS
THE CHEMICAL BASIS OF LIFE
• ELECTRON ARRANGEMENTS DETERMINE THE
CHEMICAL PROPERTIES OF AN ATOM
– VALENCE SHELLS
THE CHEMICAL BASIS OF LIFE
• ELECTRON ARRANGEMENTS DETERMINES THE
CHEMICAL PROPERTIES OF ATOMS
– WHAT IS A CHEMICAL BOND?
– WHY DO THEY OCCUR?
THE CHEMICAL BASIS OF LIFE
• CHEMICAL BONDS
– TYPES OF CHEMICAL BONDS?
– VIDEOS
THE CHEMICAL BASIS OF LIFE
• IONIC BONDS VS IONS VS IONIC COMPOUNDS
THE CHEMICAL BASIS OF LIFE
• COVALENT BONDS
THE CHEMICAL BASIS OF LIFE
• COVALENT BOND
THE CHEMICAL BASIS OF LIFE
• COVALENT BONDS FORM MOLECULES
– WHAT IS A MOLECULE?
• COVALENT BONDS ALLOW MULTIPLE
ELECTRONS TO BE SHARED AT THE SAME TIME
RESULTING IN??
– DOUBLE BONDS
– TRIPLE BONDS
THE CHEMICAL BASIS OF LIFE
• DOUBLE BONDS
THE CHEMICAL BASIS OF LIFE
• TRIPLE BONDS
THE CHEMICAL BASIS OF LIFE
• MOST IMPORTANT TYPE OF BOND??
THE CHEMICAL BASIS OF LIFE
• COVALENT BONDING DOESN’T NECESSARILY
MEAN EQUAL SHARING!!!
– POLAR VS NON-POLAR MOLECULES
– ELECTRONEGATIVITY
THE CHEMICAL BASIS OF LIFE
• WATER IS THE MOST IMPORTANT POLAR
MOLECULE
– VIDEO
THE CHEMICAL BASIS OF LIFE
• WATER’S POLARITY LEADS TO HYDROGEN
BONDING
THE CHEMICAL BASIS OF LIFE
• WATER’S POLARITY AND HYDROGEN
BONDING GIVE WATER SOME UNIQUE
PROPERTIES
– COHESION
– ADHESION
– SURFACE TENSION
– HEAT CAPACITY
– DENSITY DILEMMA?
– UNIVERSAL SOLVENT
THE CHEMICAL BASIS OF LIFE
• ACIDS AND BASES
– PH SCALE
– BUFFERS
THE CHEMICAL BASIS OF LIFE
• ACIDS VS BASES
THE CHEMICAL BASIS OF LIFE
• CHEMICAL REACTIONS REARRANGE MATTER
– H2 + O2  H2O (REACTANT VS PRODUCT??)
– C40H56 + O2 + 4H  2C20H30O (SUBSCRIPT VS
COEFFICIENT??)
THE CHEMICAL BASIS OF LIFE
• MORE TO COME!!! TUNE IN NEXT WEEK,
SAME BAT TIME, SAME BAT CHANNEL!!