Download Chapter 2 Outline 6TH PERIOD

Anatomy chapter 2 outline
The chemical composition of living matter (26-27)
• entire body is made up of thousands of chemicals interacting with one another
•matter- what the universe is made out of
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Can be seen, smelled, and felt
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Occupies space and has mass
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Exists in solid, liquid, gaseous states
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Changed physically and chemically
• physical changes- do not alter the basic nature of a substance
• chemical changes- alter the composition of the substance
• energy- is massless and does not take up space
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Only measured by its effects on matter
• kinetic energy- when energy is actually doing work
• potential energy- when it is inactive or stored
• chemical energy- is stored in the bonds of chemical substances
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When bonds are broken, the potential stored energy is unleashed and becomes kinetic
energy
• electrical energy- results from the movement of changed particles
• mechanical energy- is directly involved in moving matter
• radiant energy- travels in waves, that is, energy of the electromagnetic spectrum, which
includes x rays and infrared, visible light, radio, and ultraviolet waves
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Light energy stimulates the retinas of your eyes
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Ultraviolet waves- are responsible for that suntan we get at the beach but also
stimulates our bodies to make vitamin d
• in the body, chemical energy of foods is trapped in the bonds of a high energy chemical called
atp, and may ultimately be transformed into the electrical energy of a nerve impulse or
mechanical energy of shortening muscles
• energy cannot be created or destroyed, put the dispering parts given from heat is unusable
• all energy conversions that occur in the body liberate heat
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Heat makes us warm-blooded animals
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When matter is heated, its particles begin to move more quickly
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The higher the temperature, the faster chemical reactions occur
• elements- unique substance that cannot be broken down into simper substances by ordinary
chemical methods
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Matter is composed elements
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Ex: oxygen, carbon, gold, copper, iron
Composition of matter (pg 27-32)
1. Elements and atoms
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Elements – unique substances that cannot be broken down into simpler substances by
ordinary chemical methods
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4 elements –– carbon, oxygen, hydrogen, and nitrogen –– make up 96% of body
weight
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Periodic table – complete list of elements
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Atom – smallest part of an element that still retains its special properties
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Atomic symbol – a one- or two-letter symbol indicating a particular element
2. Atomic structure
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Atoms can be split into smaller particles
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Protons – have positive charge
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Neutrons – uncharged or neutral
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Protons and neutrons have approximately same mass (1 amu)
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Electrons – negative charged equal in strength to positive charge of protons but have s
maller mass (0 amu)
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Particles with same charge repel each other
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Particles with unlike charges attract each other
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Neutral particles neither attract nor repel by charged particles
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For any atom, the number of protons and electrons is always equal
A. Planetary and orbital models of an atom
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Planetary model – portrays the atom as a miniature solar system in which the prot
ons and neutrons are clustered at the center of the atom in the atomic nucleus
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Orbitals – regions around the nucleus in which a given electron or electron pair
is likely to be found most of the time
Orbital model – more modern model of atomic structure which has proved to be m
ore useful in predicting the chemical behavior of atoms
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It depicts the general location of electrons outside the nucleus as a haze of neg
ative charge referred to as the electron cloud
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Most of the volume of an atom is empty space
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Nearly all of the mass of an atom is concentrated in the central nucleus
3. Identifying elements
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Atoms of different elements are composed of different numbers of protons, neutrons, a
nd electrons
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Atomic number – number of protons in an atom
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Atomic number indirectly also tells us the number of electrons
Atomic mass number – sum of the protons and neutrons contained in its nucleus
A. Atomic weight and isotopes
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Atomic weight – average of the mass numbers of all of the isotopes of an element
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Isotopes – different atomic form of the same element; vary only in the number of
neutrons they contain
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Isotopes have the same atomic number but different atomic masses
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B/c all of an element’s isotopes have the same number of electrons, their chemi
cal properties are exactly the same
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Atomic weight of any element is approximately equal to the mass number of its m
ost abundant isotope
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Radioisotopes – heavier atoms that are unstable and tend to decompose to beco
me more stable
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Radioisotopes are used in minute amounts as valuable tools for medical diagno
sis and treatment
Radioactivity – the process of spontaneous decay seen in some of the heavier isot
opes, during which particles or energy are emitted from the atomic nucleus; result
s in the atom becoming more stable
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Radioactive decay are damaging to living cells
Molecules and compounds (pg 32-33)
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When two or more atoms combine chemically a molecule is formed
An example is
H+h=h2
When two or more different atoms combine they form a compound
Molecule of methane is a compound, but a molecule of hydrogen is not
Compounds have different properties from their atoms
An atom is the smallest particle of an element, and a molecule is the smallest particle of
a compound
If you break the bonds between the atoms of a compound, then the properties of the
atoms will show instead of the properties of the compound
Chemical bonds (pg.33-39)
Bond formation
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A chemical bond is an energy relationship that involves interactions between the
electrons of the reacting atoms.
Role of electrons
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Electrons occupy generally fixed spaces around the nucleus; this is called an electron
shell or energy levels.
The max number of electrons that can be in a shell is 7. They are numbered 1-7 from the
nucleus outward, so the further away from the nucleus, the more electrons there are.
The reason there are more electrons further away from the nucleus is because the
closer to the nucleus you get the stronger the pull to the positive charge there is.
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There are three layers of electron shells: inner, middle, and outer. The inner can hold up
to two electrons, the middle can hold up to eight electrons and the outer can hold up to
18 electrons.
The most important electrons are in the valence shell
-valence shell: electrons determine the chemical behavior of an atom.
When the valence shell of an atom contain 8 atoms, the atom is completely stable, but if
it contain fewer it will gain, loose, or share electrons with other atoms until it reaches a
stable state. When this happens, chemical bonds are formed.
The key to chemical reactivity is called the rule of 8s because atoms are constantly
trying to get 8 electrons.
Types of chemical bonds
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Ionic bonds: form when electron are completely transferred from one atom to another
Ions: when atoms gain or lose electrons, their charges are no longer balanced
Anions: negatively charged ions
Cation: positively charged ions ( nacl )
Covalent bonds: molecule in which atoms share electrons are called covalent molecules
and their bonds are covalent bonds. ( ch4- carbon has 4 electrons but needs 8, so
hydrogen shares 4 of its electrons so it can become active)
Hydrogen bonds: extremely weak bonds formed when a hydrogen atom bonds to 1
electron hungry nitrogen atom or oxygen atom and the hydrogen atom forms a bridge
between them.
If molecules have equally shared electrons then they are called non-polar covalently
bonded molecules.
Molecules shape determine what other atoms can interact with it
Chemical reactions (pg.33-39)
Chemical reactions
 Chemical reactions occur whenever atoms combine with or dissociate from
other atoms.
 Involve the making or breaking of bonds between atoms
o The number of atoms remain the same, but they appear in new
combinations
Types of chemical reactions
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Synthesis reactions: two or more atoms or molecules combine to form a
larger, more complex molecule. This is represented by: a + b  ab
o Always involve bond formations
o Are energy absorbing reactions
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o Underlie all anabolic activities that occur in body cells
 Particularly important for growth and for repair of worn-out or
damaged tissues
Decomposition reactions: when a molecule is broken down into smaller
molecules, atoms, or ions. Represented by: ab  a + b
o Synthesis reactions in reverse
o Bonds are always broken, and the products are smaller and simpler than
the original molecules
o Chemical energy is released as bonds are broken
o Underlie all catabolic processes that occur in body cells. They are
molecule-degrading reactions.
o The digestion of food is an example of decomposition reactions
Exchange reactions: involve both synthesis and decomposition reactions:
bonds are both made and broken.
o During exchange reactions, a switch is made between molecule parts and
different molecules are made. Represented by: ab + c  ac + b
ab + cd  ad + cb
Organic compounds (pg. 39-52)
-carbon-containing compounds
Some organic compounds are carbohydrates, lipids, proteins, nucleic acids, and adenosine
triphosphate (atp).
-carbohydrates contain carbon, hydrogen and oxygen. An example of a carbohydrate is sugars
and starches. Carbohydrates are classified by size as monosaccharides, disaccharides, and
polysaccharides.
*monosaccharides are the “simple sugars”. They are singular in structure. An example is
glucose.
*disaccharides are the “double sugars”. They are formed when 2 monosaccharides are
joined by a synthesis reaction. An example is lactose, which is found in milk.
*polysaccharides are the “many sugars”. They are long chains of linked
monosaccharides. An example is starch.
-lipids are large group of organic compounds. The most common lipids in the body are
triglycerides, phospholipids, and steroids.
*triglycerides are known as the “neutral fats”. They are composed of fatty acids and
glycerol. The molecule formed by the fatty acids and glycerol is e-shaped. They can be
either solid or liquid. Triglycerides help keep the body warm and protect body tissues.
*phospholipids are very much like triglycerides except that they have 2 fatty acids
instead of 3. The “head” of a phospholipid has an electrical charge, while the “tail” does
not.
*steroids are flat molecules formed by 4 interlocking rings. Steroids are composed of
mostly of hydrogen and carbon atoms. The most important steroid is cholesterol, which
is found in meat, eggs, and cheese.
-proteins make up over 50% of the organic matter in the body. They can play vital roles in cell
function. The building blocks of proteins are amino acids. Proteins can be classified as
either fibrous or globular.
*fibrous, or “structural”, proteins appear most often in body structures. They provide
strength in body tissues. An example is collagen.
*globular, or “functional”, proteins are mobile molecules that play large roles in
basically all biological processes. Examples are antibodies, hormones, and enzymes.
Enzymes are catalysts that regulate every chemical reaction that goes on in the body.
-enzymes are functional proteins that act as biological catalysts. A catalyst is a substance
that increases the rate of a chemical reaction without becoming a part of the product or
being changed itself. Enzymes can catalyze millions of reactions each minute. However,
enzymes can also determine which reactions are possible at any particular time.
Without enzymes, reactions would occur too slowly to sustain life.
-nucleic acids make up the genes, providing the basic blueprint for life. They direct an
organism’s growth and development. Nucleic acids are made up of nucleotides. Each
nucleotide consists of 3 parts (nitrogen containing base, pentose sugar, and a phosphate
group). The 2 major kinds of nucleic acid are deoxyribonucleic and ribonucleic. Dna is
the genetic material found in a cell’s nucleus and rna carries out the orders for protein
synthesis issued by dna. Dna is a long double chain of nucleotides, and rna molecules
are single nucleotide strands.
-adenosine triphosphate (atp) provides a form of chemical energy that is usable by all
body cells. Atp is structured like a modified nucleotide. It has an adenine base, ribose
sugar, and 3 phosphate groups. Atp is basically used to provide cellular energy.
Adenosine diphosphate (adp) accumulates energy and helps supply atp with food fuels.
Inorganic compounds – Non-carbon containing molecules that tend to be small and
simple.
Water is an example of an Inorganic compound; water has many properties that make it
important including: High heat capacity, Polarity/Solvent properties, Chemical reactivity, and
cushioning.
Another example of Inorganic compounds are Salts, which are commonly found in the body, the
most plentiful being calcium and phosphorus. Both of them being found mainly in the teeth and
bones.
Electrolytes are compounds that ionize when dissolved in suitable ionizing solvents such as
water.
Acids & Bases
Acids have a sour taste and can dissolve many metals, while bases have a more bitter taste and
feel slippery
Acids and bases are electrolytes, they ionize and then dissociate in water and then conduct an
electrical current. The higher the pH, the more basic it is.