Anatomy & Physiology I
Unit Two
Definitions
Matter – any thing that has mass
and takes up space
Therefore – all organisms as well as
the visible or unseen physical world
around them are made of matter
Definitions
Atom – the smallest particle of an
element that retains the
characteristics of the element
Element – a substance that cannot
be changed into another substance
Atom Anatomy
Electron –
negative
charge
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Neutron –
neutral
charge
Proton –
positive
charge
Periodic Chart Information
6
Chemical
Symbol
Atomic
Number (P#)
C
12.01
Atomic Mass (P# +
N#)
Atom Examples
Definitions
Isotopes –atoms of an element
that have varying numbers of
neutrons
Definitions
Molecule – a particle made up of
two or more atoms bonded
together
Diatomic molecule– two of the
same type of atom bonded together
such as O or N
2
2
Definitions
Compound – a substance made up
of two or more elements bonded
together
Therefore – the smallest particle
of a compound that retains its
characteristics is a molecule (H O
or CO )
2
2
Definitions
Ion – an atom that has given up or
gained electrons to achieve
stability
Cation – a positively charged
ion that has given up electrons
Anion – a negatively charged
ion that has gained electrons
Definitions
Electrolytes – salts that ionize in
water and form solutions capable
of conducting electricity
Therefore – electrolytes (ions)
carry a positive or negative charge
Definitions
Free radical – a chemical particle
carrying an odd number of
electrons (O2-)
Explanation – free radicals are
formed from metabolic reactions,
by radiation or chemicals
Definitions
Free radical – a chemical particle
carrying an odd number of
electrons (O2-)
Explanation – free radicals quickly
combine with other molecules
converting them into free radicals
which will destroy more molecules
Definitions
Antioxidant – a chemical that
neutralizes free radicals
Explanation – the body produces
enzymes to convert free radicals
and antioxidants are obtained
through the diet
Ionic Bonds
Bonds formed by the
attraction between ions
of opposite charges
Covalent
Bonds
Bonds formed by the
sharing of electrons
between atoms
- a covalently bonded,
polar molecule
Molecules are said to be
polar if they have slight
opposite charges on either
end
aaaaaaaaaaaaa
The slight attraction
between the negative
end of one molecule and
the positive end of
aaaaaaaaaaaaaaaaa
another results in a…
The Relative Strengths of Chemical bonds
Covalent bonds
The undisputed champion!!!
Ionic bonds
The middleweight!!
The
weakest!
Hydrogen
bonds
Definitions
Acid – a compound that releases
hydrogen (H+) ions in solution
Base – a compound that
releases hydroxide ions (OH-)
in solution
Definitions
Salt – an ionic compound that
does not contain H+ or OH-,
obtained from an acid/base
reaction
Buffer – a chemical system that
resists large changes in pH by
taking up or giving off H+
Acid-Base Reaction
Acid
Base
HCl + KOH
ClH+
K+
OH
Salt
Water
KCl + H2O
Definitions
pH – the measurement of the H+
concentration in a solution
pH – the
measurement
of the H+
concentration
in solution
Buffers
Remember – a buffer is a chemical
system that resists large changes
in pH by taking up or giving off H+
Therefore, a buffer is a
homeostatic mechanism that
helps to regulate the pH of blood
and other body fluids
Buffers
The pH range of blood is 7.357.45
It is extremely important that
blood stay in this narrow range,
making buffering systems
necessary
Buffers
The body has two types of
buffering systems:
< chemical
< physiological
A chemical buffer is a substance
that removes or releases H+ from
a system by binding to them or
releasing them
Buffers
A physiological buffer is a system
that stabilizes pH by controlling
the body’s output of acids, bases
& CO2
The two systems that act as
physiological buffers are the
respiratory and urinary systems
Chemical Buffers
The bicarbonate buffering system
CO2 + H2O
H2CO3
HCO3- + H+
The phosphate buffering system
H2 PO4-
HPO42- + H+
Chemical Buffers
The protein buffering system
-
COOH
-
COO- + H+
OR
-
NH2 + H+
-
NH3+
Physiological Buffers
The respiratory system is a two to
three times stronger buffering
system than chemical buffers
The bicarbonate buffering system
CO2 + H2O
H2CO3
HCO3- + H+
Physiological Buffers
The urinary system is most
powerful buffering system in the
body
H+ are secreted from the blood
into kidney tubules where they
bind with HCO3-, HPO42- or
ammonia
Physiological Buffers
The bound and free H+ are then
excreted in the urine
The removal of free H+ is what
makes this buffering system so
powerful
Buffering Overview
Buffering Overview
- a covalently bonded,
polar molecule
Molecules are said to be
polar if they have slight
opposite charges on either
end
aaaaaaaaaaaaa
The slight attraction
between the negative
end of one molecule and
the positive end of
aaaaaaaaaaaaaaaaa
another results in a…
aaaaa
- Polarity leads to adhesion and cohesion
-Adhesion and cohesion lead to capillary action and surface tension
- High specific heat leads to temperature stability
- High heat of vaporization leads to
evaporative cooling
aaaaa
- Spheres of hydration form electrostatic interactions, keeping ions from
interacting with each other
- This characteristic means water has a high degree of solvency and
chemical reactivity
aaaaa
- Water also ionizes into H+ and OH- which can be incorporated into other
molecules or released from them
The four types of organic compounds
Carbohydrates
Lipids
Proteins
Nucleic acids
The general formula is CH2O
The monomers are monosaccharides
Functions:
Provide energy
Structural uses
Examples:
Plants - starch, cellulose
Animals - glycogen, chitin
Functional group – COOH- (carboxyl)
The monomers are fatty acids and
alcohols
Functions:
Storage energy
Structural uses
Regulation
Protection
Examples:
•Fats (triglycerides)
•Phospholipids
•Steroids
•Waxes
The two types of fatty acids
•Saturated
•Unsaturated
Two functional groups – COOH- (carboxyl)
and NH2- (amine)
The monomers are amino acids
Functions:
Structural uses
Regulation
Protection
Provide energy
Examples:
•Collagen
•Hormones
•Enzymes
•Antibodies
The monomers are nucleotides
Nitrogen base
Functions:
Heredity
Protein synthesis
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Phosphate group
Pentose sugar
Examples:
•DNA
•RNA
Double
Single
stranded
stranded,
with three
double
helix
forms –
molecule
tRNA, rRNA,
and mRNA
Adenosine
triphosphate
The fuel of
living cells
Definitions
Dehydration synthesis – the
assembling of organic molecules by
extracting water
Hydrolysis – the breaking up of
organic molecules using water
The Metabolism
of
Macromolecules
Enzymes
Proteins that function as biological
catalysts by lowering the energy of
activation and speeding up chemical
processes
Enzymes are substrate specific, much
like a lock and key
Enzymes catalyze reactions without
being changed
Enzymes
How they work!
Enzymes
How they work!
pH effects on
enzymes
Temperature
effects on enzymes