Transcript Chemistry

Biology 211
Anatomy & Physiology I
Dr. Thompson
Some Concepts of Chemistry
For The Human Body
Recall:
SYSTEMS are composed of one or more organs,
all serving a common function
ORGANS are composed of one or more types
of tissues, all serving a common function
TISSUES are composed of one or more types
of cells and their products, all serving a
common function
CELLS are composed of different types of
organelles, all serving a common function
ORGANELLES are composed of different types
of molecules, all serving a common function
MOLECULES are composed of different types
of atoms, all serving a common function
While many types of atoms are
important in human physiology,
96% of the mass of the human body
is composed of just four elements:
These form the macromolecules
which compose the organelles of
all cells in the body
Other elements, in very small
concentrations, are primarily found
as ions:
e.g. Ca++, Na+, K+, Mg+, Fe+++, Cl-
We will not cover details of atomic structure and bonding
in lecture. These are described in your Saladin textbook.
You are responsible for studying this material and
becoming familiar with the information.
Specifically. you need to understand:
a) How protons, neutrons, and electrons form atoms; including how to
determine atomic number, atomic mass, and electrical charge
b) What ions and electrolytes are, and how these are important in
human physiology
c) How chemical formulae are written:
Structural; Condensed structural; Molecular
d) How covalent, ionic, and hydrogen bonds form
e) Differences among mixtures, colloids, solutions, and suspensions
more ….
We will not cover details of atomic structure and bonding
in lecture. These are described in your Saladin textbook.
You are responsible for studying this material and
becoming familiar with the information.
You also need to know the atomic structures of the following
“functional groups”
Amino group
Carboxyl group
Methyl group
Hydroxyl group
Phosphate group
In nature (including living cells), molecules are constantly
being broken apart to form smaller molecules, or added
together to form larger molecules
Two examples of exchange reactions
These chemical reactions occur rapidly for certain
reactions and very slowly for others
Fortunately, certain substances, called catalysts, can
make slow reactions proceed much more quickly.
In physiology,
these catalysts
are proteins
called enzymes
These reactions, building up and breaking down molecules
with the assistance of enzymes, are constantly occurring
within cells.
They allow the cell to carry out its normal functions:
- Build organelles
- Synthesize hundred of different types of molecules
- Store nutrients until it needs them
- Metabolize fuels to produce energy
- Get rid of wastes
etc.