Transcript Basic Chemistry /Chapter 2 - Wilkes

Joe Pistack MS/ED
Matter
 Matter-anything that occupies space and has weight.
 Ex. Chairs, desks, books.
 Matter exists in three states:
 Solid
 Liquid
 Gas
Solid
Solid-has a definite shape and
Volume.
Ex.
• Skin
• Bones
• teeth
Liquid
 Liquid-matter takes on
the shape of the
container that it is in.
Ex.
 Blood
 Saliva
 Digestive juices
Gas
 Gas-has no definite
shape or volume. It too
like a liquid, takes the
shape of it container
Ex.
 the air we breath.
Changes in Matter
 Matter can undergo two types of changes:
 (1) physical
 (2)chemical
 Physical change-the matter does not chemically
change, only the physical appearance changes.
 Ex. When wood is chopped from a log into smaller
pieces.
Changes in Matter
• Chemical change-occurs when the chemical
composition of the matter is changed.
• Ex. When wood is burned, wood changes to ashes.
• The human body undergoes many physical and
chemical changes.
• Ex. Chewing is a physical change, breaks food into
smaller pieces and digestion is a chemical change, it
changes the food into simpler substances.
Elements
• Element-fundamental substance that cannot be broken
down into a simpler form by ordinary chemical reactions.
• All matter living or dead is composed of elements.
• Four elements make up 96% of the body:
• Carbon
• Hydrogen
• Oxygen
• Nitrogen
Elements
• Trace elements-present in small amounts, but are
essential for life.
• Atom-smallest unit of an element with that element’s
chemical characteristics. All elements are composed
of atoms.
• Atoms are composed of:
protons
neutrons
electrons
Trace Elements
 Elements that are present in tiny amounts.
 Essential for life.
 Ex. Iodine , Chromium
Cobalt , Copper
Florine, Zinc
Atomic Structure
 Atom-smallest unit of an element with that element’s
chemical characteristic
 Composed of three subatomic particles:
 Protons
 Neutrons
 electrons
Atomic Structure
 Protons and neutrons are located in the nucleus.
 Protons carry a (+) electrical charge.
 Electrons carry a (-) electrical charge.
 Neutrons carry no electrical charge.
Atomic Structure
 Atom that have an equal number of protons and
electrons are electrically neutral, and carry no
electrical charge.
 The number of protons and electrons in an atom is
what makes atoms different.
Atomic Structure
 Two important characteristics of atoms:
 (1) Atomic number-the number of protons in the
nucleus.
 (2) Atomic weight-determined by adding the number
of protons and neutrons in the nucleus.
Atomic Structure
 Isotope-different form of the same atom.
 Isotopes are unstable, nuclei break down or decay
which gives off particles as energy waves.
 Unstable nuclei become more stable. Unstable
isotopes are called radioisotopes.
Radioactivity
 Radioactivity-the process of spontaneous breakdown.
 Radioisotopes are damaging to tissue and are used
clinically to destroy cells.
 Ex. Radioactive iodine is used to destroy excess thyroid
tissue. Certain radioisotopes are used to destroy
cancer cells.
Chemical Bonds
 Chemical bond-the attraction between the atoms.
 Three types of chemical bonds:
 (1) ionic bonds
 (2) covalent bonds
 (3) hydrogen bonds
Chemical Bonds
 Ionic bonds-caused by a transfer of electrons between
atoms.
 Covalent bonds-involves the sharing of electrons by
the outer shells of the atoms.
 Hydrogen bonds- is not caused by either the transfer
or the sharing of electrons of the outer shells of atoms.
Ions
 Ions-elements that carry an electrical charge.
 Cation-positively charged ion.
 Anion-negatively charged ion.
 Ions are formed when electrons in the outer shell are
either gained or lost.
Electrolytes
 Electrolyte- substance that forms ions when it is
dissolved in water.
 Ionization-the process where an electrolyte splits, or
breaks apart in solution. (dissociates)
Electrolytes
 One of the most important clinical tools in assessing a
patient.
 Help the physician to make a diagnosis.
 May be life threatening if too high or too low.
 Also called “lytes”.
Common Cations
Name
Sodium
Symbol
Na+
Calcium
Ca2+
Iron
Fe2+
Hydrogen
H+
Potassium
K+
Ammonium
NH4
Function
Fluid balance, nerve-muscle
function.
Bones, teeth, blood clotting,
muscle contraction.
Oxygen transport, component of
hemoglobin.
Acid-base balance.
Nerve and muscle function, chief
Intracellular cation.
Acid-base regulation.
Common Anions
Name
Chloride
Symbol
Cl-
Bicarbonate
Function
Primary extracellular anion.
Acid-base regulation.
HCO3Phosphate
PO3/4
Bones and teeth, component
of
ATP, (energy).
Molecules
 Molecule-formed when two or more atoms bond
together.
 Two identical atoms may bond, or atoms from two
different elements may combine.
 Ex. When one atom of oxygen bonds with another
atom of oxygen to form a molecule of oxygen, this is
designated O2.
Molecules
 Ex. of atoms of two different elements combining:
 Two atoms of hydrogen combine with one atom of
oxygen to form a molecule of water (H2O).
Compound
 Compound-a substance that contains molecules
formed by two or more different atoms.
 Ex. If two atoms of hydrogen combine with one atom
of oxygen, water is formed, (H2O).
 Water is considered both a molecule and a compound.
Water
Water
 The most abundant compound in the body.
 Constitutes approximately 2/3 of an adults body
weight.
 Essential for life.
 Can only survive a few days without water.
Compounds
 Carbon Dioxide-compound consisting of one carbon
atom and two oxygen atoms (C02).
 CO2 is made when food is chemically broken down for
energy.
 CO2 is a waste product so it must be eliminated from
the body.
Water
 Important facts about water:
 Universal solvent-most substances dissolve in water.
 Temperature regulator-has the ability to absorb
large amounts of heat. Plays a role in temperature
regulation.
 Lubricant-major component of mucous and
lubricating fluids.
 Cushion- helps absorbs impacts throughout the body
and within joints
Molecules
 Oxygen-(O2)
 A molecule composed of two
oxygen atoms.
 Exists as a gas.
 Air we breath contains 21%
oxygen.
 Oxygen is essential for life.
 Oxygen gives us energy.
Chemical Reactions
 Chemical reaction-process whereby atoms of
molecules or compounds interact to form new
chemical combinations.
 The rate of the chemical reaction or how fast they
occur is important.
 If the rate of the reaction needs to be increased, a
chemical substance called a catalyst is used.
Acids And Bases
 A normally functioning body requires a balance
between acids and bases.
 Acid-base balance is important because the chemical
reactions in the body occur when these substances are
in balance.
 Imbalances of acids and bases cause life-threatening
clinical problems.
Acids
 Acidic foods that we eat
generally have a sour taste.
 Grapefruit juice, orange
juice, lemons, and vinegar
are examples of acids.
 Very strong acids, such as
hydrochloric acid (HCl)
can cause burns and
damage tissue.
Acids
 Acid-an electrolyte that dissociates into a hydrogen
ion (H+) and an ion.
 Strong acid-dissociates completely into H+ and an
ion.
 Weak acid-does not dissociate completely.
Bases
 Base-has a bitter taste and is slippery like soap.
 Bases usually contain the hydroxyl ion (OH-).
 When an acid mixes with a base, the H+ of the acid
combines with the OH- of the base to form water.
This neutralizes the acid.
The pH Scale
 pH-unit of measurement that indicates how many H+
are in a solution.
 The pH Scale ranges from 0 to 14.
 Midpoint of the scale is 7, this is the point where the
number of hydrogen ions (H+) in pure water is equal
to the number of hydroxyl ions (OH-).
The pH Scale
 A pH that measures less
than 7 on the scale
indicates that the solution
has more hydrogen ions
(H+) than hydroxyl
ions(OH-). The solution is
said to be acidic.
 A solution that measures
more than 7 indicates
fewer hydrogen ions (H+)
than hydroxyl ions (OH-)
is said to be basic or
alkaline.
The pH scale
The pH Scale
 The pH scale measures the degree of acidity (acid) or
alkalinity (base).
 Normal pH of blood is 7.35 to 7.45 and is slightly
alkaline.
 When pH falls below 7.35 the patient is said to be
acidotic. When pH rises above 7.45, the patient is said
to be alkalotic.
The pH Scale
 The body needs to remain in a normal alkaline state to
function normally, during periods of illness the
patient’s blood pH will be monitored.
 Blood pH is regulated by three mechanisms:
(1) buffers
(2) lungs
(3) kidneys
The pH Scale
 Patient’s with ulcers often have excess stomach acid.
 Stomach acid can be neutralized with a drug that
contains a base.
 These types of drugs counteract acids so they are
called antacids.
Energy
 Energy-the ability of the body to perform work.
The body depends on a continuous supply of energy.
 Mechanical energy-energy that causes movement.
Ex. Running, walking, contractions of the heart.
 Chemical energy-energy that is stored, gives us the
fuel to do work.
Energy
 Energy can be converted from one form to another.
 Thermal energy-energy transferred because of a
temperature difference, responsible for body
temperature.
 Radiant energy-energy that travels in waves,
stimulates the eyes for vision.
ATP
 Energy that is used to power the body comes from the
food that we eat.
 As food is broken down, energy is released.
 The energy is not used directly by the cells of the body,
must be transferred to a substance called adenosine
triphosphate (ATP)
ATP
 The energy released from the ATP is the energy that
can be used directly by the cells to perform tasks.
 ATP is a high energy chemical bond that is composed
of three phosphate groups, a sugar and a base.
Mixture
 Mixture-combination of
two or more substances
that can be separated by
ordinary physical means.
 When separated, the
substances retain their
original properties.
Solutions
 Solutions-mixtures, the
particles that are mixed
together remain evenly
distributed .
 A solution has two parts:
the solute, the substance
that is present in the
smaller amount and the
solvent, the part of the
solution that is present in
greater amounts. The
solvent is usually liquid.
Solutions
 Aqueous solution-when water is used as the solvent.
 Tincture-when alcohol is used as the solvent.
 A solution is always clear and the solute does not settle
to the bottom .
Suspensions
 Suspensions-mixtures,
particles are relatively large
and tend to settle to the
bottom unless the mixture is
shaken continuously.
 Ex. Sand and water .
 Colloidal suspension-
particles do not dissolve, very
small and remain suspended
within the liquid. Colloid is
a gel-like substance that
resembles egg whites.