Download Anatomy Chapter 2 Outline

Anatomy Chapter 2 Outline
Concepts of matter and energy pg. 26-27
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Matter- is anything that occupies space and has weight
Matter can be found in 3 forms
Solid, liquid, and gas
Solids- have a definitive shape and volume
Liquids- have a definitive volume but they conform to the shape of their container
Gases- have neither a definitive shape nor volume
Matter can have both physical and chemical changes
A physical change does not alter the basic nature of the substance
A chemical change do alter the composition of the substance
There are 2 types of energy
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Kinetic- energy doing work
Potential- inactive stored energy
All living things are built of matter to live and function
Forms of energy
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Chemical energy- stored in bonds of chemical substance
Electrical energy- movement of charged particles
Mechanical energy-is directly involved in moving matter
Radiant energy-travels in waves, the electromagnetic spectrum
Energy forms conversions
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Energy can go from one form to another quickly.
Energy can affect body temp. And also the bodies functioning.
When your body heats up is can be a form of Kinetic energy
This chemical reaction in your body is what keeps you alive and functioning today.
Composition of Matter (pg. 27-32)
Elements and Atoms
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All matter is composed of a limited number of substances called elements.
Elements cannot be broken down into simpler substances by ordinary chemical
methods
There are 112 elements known with certainty
*92 are produced naturally
*The rest are produced artificially in accelerator devices
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Carbon, Hydrogen, Oxygen, and Nitrogen make up about 96% of body weight.
A complete listing of the elements appears on the periodic table
*The building block of an element is called an atom
* The atoms of each element differ from those of other elements
* Each element is designated by a one or two letter chemical shorthand called an
atomic
Symbol (Example: C stands for carbon, O for oxygen, and Ca for calcium.)
Atomic Structure
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Atoms are clusters of smaller (subatomic) particles. Under special circumstances, atoms
can be split into these smaller particles.
An atom loses the unique properties of its element when it’s split into subparticles.
Protons (p+) have a positive charge, Neutrons (n0) have a neutral charge. They are
heavy particles and approximately weighs the same. (1 atomic mass unit)
Electrons (e-) have a negative charge. Has the same strength as a positive charge but
their mass is so small that it’s 0 atomic mass unit.
The Electrical charge is a measure of its ability to attract and repel each other charged
particles.
*Particles with the same charge repel each other
* Particles with opposite charges attract each other
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*Particles with neutral charges do not attract or repel
Because all atoms are electrically neutral, the number of protons and neutrons must be
equal to each other.
Planetary and Orbital Models of an Atom
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Planetary Model of an atom portrays the atom as a miniature solar system. The protons
and neutrons are clustered together at the center of the atom in the atomic nucleus.
The nucleus is dense and positively charged.
The electrons orbit around the nucleus. We cannot determine the exact location
because electrons jump around unknown paths.
So instead, chemists talk about orbitals which are regions around the nucleus where an
electron or an electron pair are most likely found.
The more modern model of atomic structure is called the orbital model, which has been
proved more useful in prediction the chemical behavior in atoms.
Identifying Elements
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All protons are alike
The same is true with neurons and electrons
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However, atoms of different elements are composed of different numbers of protons,
electrons, and neutrons.
All known atoms can be described by adding one proton and one electron at each step.
The number of neutrons are harder to understand. However, light atoms have equal
numbers of protons and neutrons but in larger atoms there are more neutrons than
protons.
Atomic Number
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Each element is given an atomic number
The atomic number is equal to the number of protons its atoms contain
Atoms of each element contain a different number of protons than atoms of any other
element.
The number of protons are always equal to the number of electrons.
The atomic number indirectly tells us the number of electrons the atom contains
Atomic Mass Number
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The atomic mass number of any atom is the sum of the protons and neutrons
contained in its nucleus.
(Example: Hydrogen has one bare proton and no neutrons. So its atomic number and
atomic mass number is the same which is 1)
Atomic Weight and Isotopes
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Atomic weight is the average of the mass numbers of all of the isotopes of an element
Isotopes have the same number of protons and electrons but vary in the number of
neutrons they contain.
Therefore, the isotopes of an element have the same atomic number but have different
atomic masses.
An element’s isotopes have the same number of electrons their chemical properties are
exactly the same.
The atomic weight of any element is approximately equal to the mass number of its
most abundant isotope.
Radioisotopes are the heavier isotopes of certain atoms are unstable and tend to
decompose to become more stable.
Radioactivity is the process of spontaneous atomic decay. It can be compared to a tiny
explosion.
*All types of radioactive decay involve the ejection of alpha and beta particles or
gamma
rays from the atom’s nucleus and are damaging to living cells.
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Ionizing radiation does not damage the atoms in the path directly. It sends electrons
flying. It’s the electrons that does the damage.
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Radioisotopes are used as valuable tools for medical diagnosis and treatment and to
treat things like localized cancers.
Molecules and Compounds Pg.32-33
Molecule- When 2 or more of the same atoms combine chemically (Ex. H+H-> H2)
Compound- When two or more different atoms bind together to form a molecule
(Ex. 4H+C-> CH4)
Molecular Formula- The formula that shows what different atoms make a molecule or
compound (Ex. H+H, 2H+O)
Chemical Equation- The whole equation including the Molecular formula and what it yields
(Ex. H+H->H2, 2H+O->H2O)
Chemical bonds and chemical reactions (pg 33-39)
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Bond formation is the interactions between the energies of the electrons
Electrons occupy fixed spaces around the nucleus (i.e. electron shell, energy
levels)
Electrons are influenced by other atoms as the get further from nucleus
Electrons in valence shell determines chemical behavior
If the valence shell contains 8 electrons, it is stable and doesn’t react
If the valence shell contains less than 8, it loses, shares, or gains an atom to reach
8 electrons
Having 8 electrons in valence shell is key to reactivity
Ionic bonds form when electrons are completely transferred from one atom to
another
When an atom loses or gains an electron during bonding, they become ions
Negatively charged ions are called anions
Positively charged ions are called cations
Sodium chloride and other compounds formed by ionic bonding usually falls
under the category of salts
Covalent bonds are formed when molecules share an electron
Covalent molecules share the electron equally between the atoms of the molecules
Hydrogen bonds are weak bonds formed by a hydrogen atom bound to one
electron-hungry nitrogen or oxygen atom is attracted to another electron atom and
the bond forms a bridge between them
Synthesis reactions occur when two or more atoms/molecules combine to form a
larger, more complex molecule
Decomposition reactions occur when a molecule is broken down into smaller
atoms, or ions
Exchange reactions occur when bond both are made and broken
Biochemistry: The Chemical Composition of Living Matter (pg.39-52)
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2 major classes of molecules in the body: inorganic compounds and organic compounds
inorganic compounds lack carbon and tend to be small and simple
-example: water, salts
organic compounds are more complex and are carbon-containing
-example: carbohydrates, lipids, proteins, nucleic acids
I. Inorganic Compounds
A. Water
 Most abundant in the body (2/3)
 Properties that make water so vital:
1. high heat capacity-absorbs and releases larges amounts of heat before its
temperature changes appreciably
2. polarity/solvent properties-water = “universal solvent”
-solvent =liquid or gas in which small amounts of other substances (solute)
can be dissolved
-solute+solvent=solution
-respiratory gases and waste can dissolve in water
-mucus and saliva use water as their solvent
3. chemical reactivity-water=important type of reaction
-water molecules are added to the larger bonds to
digest
foods and break down biological
molecules (hydrolysis reaction)
3. cushioning- water serves as a protective function; it
forms a cushion
around the brain to protect it
from trauma
B. Salts
 Most plentiful salts contain calcium and phosphorus which are found in
bones and teeth
 Dissociation-when salt dissolves in the body and separates its ions
 Vital to body functioning
 All salts are electrolytes which are substances that conduct an electric
current in a solution
C. Acids and Bases
1. Characteristics of Acids
 Sour taste, can dissolve metal
 Acid: a substance that can release hydrogen ions in detectable amounts
 Proton donors
 Acids in the body: hydrochloric, acetic, carbonic acids
 Strong vs. weak acids
2. Characteristics of Bases
 Bitter taste, slippery
 Proton acceptors
 Hydroxides are common inorganic bases
 Any base containing the hydroxyl ion is a strong base
 Bicarbonate ion (in blood) is weaker
 When acids and bases mix, they form water and salt
 Neutralization reaction: when an acid and a base react
3. pH: Acid-Base Concentrations
 pH units- the relative concentration of hydrogen ions in various body
fluids is measured in concentration units called pH
 pH scale- 1990 by Sorensen and is based on the # of protons in solution
expressed in term of moles per liter (mole=concentration unit)
 pH scale 014; 7= midpoint (neutral), 1-6=acid,
8-14=base
 1 stronger acid; 14=weaker base
 living cells are extraordinarily sensitive to even slight changes in pH
 acid-base balance is regulated by the kidney, lungs, and a # of chemicals
called buffers (present in body fluids)
 weak acids and weak bases=important to the body’s buffer systems
which act to maintain pH stability
 regulation of blood pH ranges from 7.35-7.45
 small change in blood pH threatens death
 when blood pH begins to dip into the acid range, the amount of lifesustaining oxygen that the hemoglobin in blood can carry to body cells
begins to fall rapidly to dangerously low levels