Zusammenfassung der Ressource
Martini Chapter 2 - Part 1
- Chemical Organisation
- Atoms - Protons,
Electrons and
Neutrons
- Elements
and their
isotopes
- Atomic weight
- Moles
- Electrons and Shells
- Each shell
has different
energy levels
- the outer shell is
the valence shell
- the number of
electrons in the outer
shell determine the
chemical properties
of the element
- Chemical Bonding
- Ionic bonds
- cations -
positive ions
- anions -
negative ions
- form from the attraction
between cations and
anions, the anion
donates electron(s) to the
cation
- Covalent bonds
- atoms share
electrons
- single, double and
triple bonds exist
- non polar covalent bonds
- the elections sit half way
between the 2 atoms as
there is an equal attraction
- polar covalent bonds -
the electrons are pulled
closer to one of the atoms
as they have a stronger
pull from the nucleus
- hydrogen bonds
- the attraction between a
polar hydrogen atom in a
molecule and the
negatively polar atom in
another molecule, the
most common atom is
oxygen which has is
negatively polar
- states of matter
- solids, liquids and gases
- molecular weights
- sum of atomic
weights
- Chemical reactions in physiology
- Basic Energy Concepts
- Kinetic - energy of motion
- Potential -
stored energy
- Types of Chemical Reactions
- Decomposition
- breaking a
molecule into it
constituents
- hydrolysis is a
common form of
decomposition
- catobolism -
decomposition
of complex
molecules in the
body's cells and
tissues
- Synthesis
- the opposite of decomposition,
it forms a molecule using its
constituents
- dehydration synthesis is
sythesis by the removal
of a water molecule
- anabolism - synthesis of
complex molecules in the
body's cells and tissues
- Exchange
- parts of 2 reacting
molecules are shuffled
around to form new products
- Reversible
- reactions that can
happen both ways
- they rest at equilibrium
where both reactions
are happening at a
constant level
- Enzymes
- lower the
activation
energy
- act as catalysts
- speeds up the
rate of the reaction
- exergonic - reactions
that release energy
- endergonic - reactions
that use up energy
- Systems dependant on water
- Solubility
- many organic
and inorganic
molecules are
soluble
- solution - the mixture of
particles and water
- solvent -
the liquid
e.g. water
- solute - the particle that
is dissolved in the solvent
- Reactivity
- many reactions take
place in water
- many reactions
use water
- High Heat
Capacity
- ability to
absorb and
retain heat
- water has a high
heat capacity
because of its
hydrogen bonding
- Lubrication
- there is little
friction between
water molecules
- Properties of Aqueous Solutions
- water molecules
are polar
- in water ionic
bonds are broken or
dissociated/ionised
- ionised solutions contain
the anions and cations of
the orginal molecule
- Electrolytes
and Body Fluids
- electrolytes - soluble
inorganic ions that conduct
electricity in solution
- changes in
concentrations of
electrolytes effects
body fluids and
every vital function
- concentrations of ions are
regulated by the kidneys (ion
excretion), the digestive tract
(ion absorption) and the skeletal
system (ion storage or release)
- hydrophilic
- Hydrophilic and phobic Compounds
- polar covalent bonds attract water molecules
- hydration spheres form carry
these molecules into solution
- non polar molecules can't form
the hydration sphere so don't
dissolve they are hydrophobic
- Colloids and Suspensions
- A solution containing proteins and other large molecules is called a colloid.
- the particles in a colloid will remain in solution indefinitely.
- A suspension contains large particles that
settle out of the solution by the force of gravity
- Body Fluid pH
- Hydrogen ions can break
chemical bonds and change the
shape of complex molecules and
distrupt cell and tissue functions
- Hydrogen ion
concentration must
be strictly regulated
- the pH is -log10[hydrogen
ion concentration]
- pH 7 is neutral
- pH<7 is acidic
- pH>7 is alkaline
- blood pH is
between 7.35
and 7.45
- blood pH of less
than 7.35 is acidosis
and below 7 causes
a coma and then
death
- blood pH of more than
7.45 is alkalosis, above
7.8 causes uncontrollable
skeletal muscle spasms
- Acids, Bases and salts physiological roles
- A weak acid
only partically
dissociates in
solution
- A strong acid fully
dissociates in solution
- Weak acids
and bases
form
equilibriums
- Salts
- A salt is an ionic compound
containing any cation
excluding hydrogen ions
and any anion excluding
hydroxide ions
- salts
dissociate in
water into their
respective
cation and
anion
- Buffers and pH control
- Buffers resist
any changes in
pH by removing
or adding
hydrogen ions
- Buffers form from a weak
acid and its conjugate base