Chemistry of Life

• Living things are:

  96% Oxygen, Carbon, Hydrogen, & Nitrogen

  4% Calcium, Phosphorus, Potassium, Sulfur, Sodium, Chlorine, & Magnesium

  <0.01% Iron, Zinc, Copper etc.
• Matter consists of elements which are substances that cannot be broken down to other substances by chemical reaction
• A compound is a substance consisting of 2 or more different elements combined in a fixed ratio; it is made of atoms joined by bonds
• An atom is the smallest unit of matter that still retains the property of an element
• A molecule is 2 or more atoms held together by covalent bonds
• A covalent bond is the sharing of a pair of valence electrons by 2 atoms
• Strong bonds include: non-polar covalent bonds, polar covalent bonds, and ionic bonds
• In non-polar covalent bonds, atoms have equal electronegativity
• In polar covalent bonds, atoms have unequal electronegativities
• An example of an ionic bond is table salt (NaCl)
• Weak bonds include hydrogen bonds and van der waals interactions
• In hydrogen bonds, Hydrogen atoms covalently bonded to electronegative atoms become partially positively charged thus allowing them to non-covalently bond to other electronegative atoms
• In Van der Waals interactions, electron accumulations cause positive & negative regions which may bond
• Acids donate protons while bases accept protons
• Buffers act as sponges for acidic & basic ions
• Water is a solvent as it enables molecules to float and interact through bonding. It creates a hydration shell
• Organic chemistry is the study of carbon compounds
• Carbon forms diverse molecules by bonding to 4 other atoms i.e. carbon skeletons
• Carbon skeletons can have 4 shapes: length, branching, double bond, and ring
• Carbon insolubility in water contributes to biomolecule roles
• Bonds can be an energy store
• Isomers are compounds with the same numbers of atoms of the same elements but with different structures and hence different properties
• Functional groups are chemical groups directly involved in chemical reactions, each with certain chemical properties
• An ionic bond is when an electron is completely transferred from one atom to another