Chemistry of Life

 

A. Levels of Chemical Organization

Matter – Has mass (difference between mass and weight) and occupies space

1.    Atoms

a.     Composed of several types of subatomic particles, including neutrons, protons, and electrons.

b.    Nucleus at core

Protons – positively charged

Neutrons – uncharged, same mass as protons

c.     Electrons – negatively charged, move around nucleus at a distance in orbitals. Orbitals hold 2 electrons.  Even though the mass is very different from protons the charge is opposite, but equal.  One electron per proton, keeps elements electrically neutral.

d.    Atomic number = # protons (subscript)

e.    Atomic mass number = # protons+#neutrons (superscript)

f.       Isotopes – more neutrons

g.    Radioactive isotopes, alpha particles (He nuclei), beta particles (electrons), gamma rays

 

 

2.    Elements, Molecules, and Compounds

a.     elements – pure, one kind of atom

b.    molecules – combinations of atoms

c.     compounds – pure substances with the same kind of molecules, molecules have more than one element

 

Show how to write formulas. 

 

Explain periodic table a bit, and orbitals.

 

96% Human body consists of CONH (98% CHNOPS)

 

B. Chemical Bonding

 

Fill shells, share, donate, accept (borrow) electrons, match closest noble gas, rule of eights.

 

1.    Ionic Bonds

 

Donate/borrow (accept)

 

2.    Covalent Bonds

 

Share; H2, O2,  H2O

 

C. Inorganic Chemistry: No C-C or C-H covalent bonds, not really many carbon atoms at all

 

1.    Water: solvent (solutes, aqueous solution)

 

 

a.     Unequal sharing, hydrogen bonding

 

b.    Cohesive, heat of evaporation and liquification

 

c.     Solvent, dissolves polar substances

 

d.    Dissociation of water, small degree of ionzation (only 10^-7 moles)

 

2.    Electrolytes: substances that break apart and release ions when put into water (conduct electrical current)

 

3.    Acids, Bases, and Salts:

 

a.     acids = proton donors

 

b.    bases = OH- providers or proton acceptors

 

c.     HCl + H₂O ® H⁺ + Cl-

 

d.    pH scale and how it works, H₂O « H⁺ + OH-

 

e.    Strong acids and bases, salts; HCL + NaOH ® H₂O + NaCl

 

f.       Buffers – helps keep pH constant, takes up excess H⁺ and OH^-

 

 

D. Organic Chemistry – carbon containing, C-C and C-H covalent  bonds,

 

1.    Carbohydrates: C + H₂O; mono-, di- (sucrose, table; fructose, fruit; lactose, milk), and polysaccarides (glycogen and starch)

 

2.    Lipids: fats and oils, Triglycerides, phosopholipids, steroids (cholesterol)

 

3.    Proteins: amino acids, peptide bonds, folding – electrostatic interactions.  Structural vs functional, enzymes (lock and key model)

 

4.    Nucleic Acids: Code of life, DNA and RNA, double helix, ACTG except U, mRNA.