CHEMISTRY:

"Inorganic chemistry" is an expression for first year college chemistry.
Second year college chemistry is "organic chemistry," the chemistry of carbon (C) based molecules.
In Bio 104, we have the good fortune of summarizing these 2 yrs of chemistry in a few lectures!

Substance is composed of Mass (matter), and Energy is also important, but, in biology, we will focus only on that energy which is biologically useful.

INORGANIC CHEMISTRY
From the Los Alamos National Labs (periodic table) [note the back arrow does not work]
TRANSPARENCY (Fig. 2.10) shows some information from the first few rows of this table.
(Note the electrons and the nucleus.)
Periodic table - elements - O, C, H, Ca, P, K, S, ... are most abundant in life
TRANSPARENCY (Table 2.1) shows this.
There are also trace materials like iron and zinc.

Atoms = Elements
There are 3 particles.
TRANSPARENCY (Fig. 2.5) elaborates on Fig. 2.10, showing nucleus has neutrons and protons.
1. Protons determine the atomic number (integers in order, top of each box on the periodic table).
2. Neutrons plus protons determne weight (bottom of box). These are not integers because there are several isotopes such as 3H (tritium), 14C. The 14 is a superscript, and this is pronounced "C-14." Isotopes are radioactive, and decay with a characteristic half-life. In biology, radioactive isotopes are used for radiocarbon dating and to label molecules (radioactive tracers) and for autoradiography (exposing film).
TRANSPARENCY (Fig. 2.6) shows quantifying radioactivity in a scintillation counter (note, she should also be wearing safety goggles!) and microscopic audoradiography.
3. electrons, virtually no mass, involved in bonding of two major types:
(a) covalent bonding
(b) NaCl splits to Na+ (sodium) and Cl- (chloride) ions that are attracted to each other because of opposite charges TRANSPARENCY (Fig. 3.7)
If light is absorbed by a pigment, the electron is excited, and, if the molecule fluoresces, the exctation in the electron comes back down; electrons will be very important in our discussion of how biological energy is stored (photosynthesis) and how it is released (cellular respiration)

This page was last updated 6/07/02

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