"Inorganic chemistry" is an expression for first year college
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.
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
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
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
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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