Show Menu

AP Bio Chemistry of life Cheat Sheet by

AP Biology Class notes from Dr. George's class turned into a study guide on Chemistry of life.


Everything is made up of matter
Only 25 elements are essential for life
Matter is made up of atoms
96% of living matter is N,H,C,O
Atoms consist of protons, Neutrons, and Electrons
4% of living matter is Ca,K,S,P

Bonding Properties

Electron Effects-
determine chemical behavior of atom
depends on the # of the electrons in the outermost shell called the "­valance electr­ons­" & "­Valance shell"
atoms want a complete octate (8 valance electrons) except for hydrogen (wants 4)

Chemical Reactivity

Atoms tend to complete a partially filled valance shell or empty a partially filled valance shell.
This drives reactions & completes bonds

Bonds in chemistry

Strong Bonds
Weak Bonds
Covalent Bond -> share electrons evenly
Hydrogen Bond -> attraction between + and -

Covalent Bonds

Why are covalent bonds so strong?
Multiple covalent bonds
* 2 atoms share a pair of electrons
* Double Bonds ex: O2
* both atoms are holding on
* 2 Pairs of electrons
* Very stable
* Triple bonds ex: N2 (very strong)
* Forms Molecules ex: H2O
* 3 pairs of electrons

Polar vs Non Polar Covalent Bonds

Polar Covalent
Non-Polar Covalent
No areas of + or - because electrons are shared evenly
Electrons are shared unequally by atoms
Ex: Hydroc­arbons (Methane CH4)
Ex: (H2O) -> O is more - and pulls electrons away from the H making O have a - charge.
Balanced and stable

Hydrogen Bonding

Attraction between +H in one H2O molecule and the -O in another H2O molecule
Weak Bond


No comments yet. Add yours below!

Add a Comment

Your Comment

Please enter your name.

    Please enter your email address

      Please enter your Comment.

          Related Cheat Sheets

          Properties of water Cheat Sheet

          More Cheat Sheets by STEMhighschool

          Properties of water Cheat Sheet