A clear understanding of chemistry is
essential for the study of physiology.
This is because organ functions
depends on cellular functions, which
occur as a result of chemical reactions.
Watson & Crick first proposed the
double helix structure of DNA
Biochemistry = Chemistry of living things
Matter = Anything that has mass and takes up space
(Solids, liquids, gasses)
Element = Fundamental substance of matter
(e.g. Carbon, Hydrogen, Oxygen)
Compound = Two or more different elements chemically bonded
together (e.g. H2O = water, C6H12O6 = glucose)
Molecule = two or more atoms chemically joined together.
Molecules may be compounds (H2O = water molecule), or
Molecules may be of the same element (H2= hydrogen molecule)
Our body consists of 11 bulk elements and 7 trace elements.
Bulk elements make up 99.9% of our body:
Trace elements make up less than 0.1% of our body:
Learn each bulk element and trace element along
with their atomic symbols shown in parentheses
All elements are arranged onto a Periodic table
Atoms are the smallest particles of an element that still
have the properties of that element.
Atoms are composted of 3 subatomic particles:
Proton – carries a single positive charge
Neutron – carries no electrical charge
Electron – carries a single negative charge
An atom contains a central nucleus
composed of protons and neutrons.
Electrons orbit the nucleus.
Proton: +1 charge.
Electron: -1 charge.
Neutron: 0 charge
Proton: 1 dalton
Neutron: 1 dalton
Most atoms contain equal number of protons and electrons, so
an atom contains no overall net charge and is neutral.
Atomic Number: The number of protons in one atom.
Atomic number identifies an element.
Example. The atomic number of oxygen is 8. Oxygen, and
only oxygen has 8 protons.
Atomic Weight: The sum of protons and neutrons in one atom.
Remember, the weight of electrons is negligible.
Isotopes are atoms with the same atomic number, but different
atomic weights. Isotopes occur because the number of neutrons of
an element varies between atoms.
Two isotopes of oxygen:
Oxygen 16 (O16)
Oxygen 17 (O17)
*The atomic weight of an element is an average of the isotopes present.
Understand the notations on a periodic table.
End of Section 1, Chapter 2
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