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Ch 2 – Chemistry
Matter: has mass and occupies a volume of space
Can exist in various states
Solid: mass and definite shape
Liquid: mass, but takes the shape of its container
Gas: mass, and takes the shape of its container
Air is a gas: mixture of several gaseous
elements and compounds (Nitrogen, Oxygen, Argon,
Helium, Carbon Dioxide)
Plasma State (ionized gas)
Solid -> liquid -> Gas
1-Elements – basic substance (e.g., Iron, Sodium,
Potassium)
2-Compounds – 2 or more elements that are
chemically bonded together (water, glucose C6H12O)
a. Molecules
b. Ionic Compounds
3-Mixtures – 2 or more combinations of elements and
or compounds (e.g., mayonnaise)
Elements are made up of atoms
Atoms consist of sub-atomic particles
Nucleus: at center of the atom; will consist of
proton, neutrons
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Orbits: distinct/discrete which may be occupied
by the sub-atomic particle called the electron
Every element will have their own unique number of
protons (which equals the number of electrons)
Proton Positively charge (+); has mass
Neutron Bears no charge;
has mass (about same as P)
Electron Negatively charge (-); has mass
1830 electrons = mass of 1 proton
Element has
Atomic number (number of protons)
Atomic mass (grams per mole); amu (atomic
mass unit)
Elemental symbol:
H for Hydrogen
C for Carbon
O for Oxygen
N for Nitrogen
S for Sulfur
P for Phosphorous
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C
6
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Elements have been arranged in order of their atomic
number: periodic table
92 naturally occurring elements
118 total elements
Isotope: form of an element that differs ONLY in
atomic weight, NOT in atomic number
H
D
T
P
1
1
1
E
1
1
1
N
0
1
2
3
Atomic Mass
1
2
3
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Atomic weight: average weight obtained from the
weights of all the isotopes
P
E
N
Atomic mass
12
6
6
6
12
C
13
C 6
6
7
13
14
C 6
6
8
14
To determine number of neutrons
Atomic weight – number of protons = num of
neutrons
Isotopes – Radioactive
Emit high energy electrons (beta particles)
Alpha particles (He +2)
Gamma rays
Cobalt
See:
http://www.colorado.edu/physics/2000/isotopes/inde
x.html
http://ie.lbl.gov/education/isotopes.htm
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Atomic Weight/Atomic Mass
= weighted average of atomic masses of isotopes of
element
e.g., atomic weight of carbon = % abundance of
carbon-12 x its atomic weight + % abundance of
carbon-13 x its atomic weight + % abundance of
carbon-14 x its atomic weight
http://en.wikipedia.org/wiki/Electromagnetic_spectru
m
Light – Electromagnetic Spectrum
Radiowaves (lowest energetic light), microwaves,
infrared red, visible spectrum, ultraviolet, x-rays,
gamma rays, cosmic rays (highest energetic light)
White light -> prism -> rainbow (red, orange, yellow,
green, blue, indigo, violet)
CT Scans
Chemical Bonding
1) Ionic Bond
2) Covalent Bond
Electron
Inner shell electrons
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Outer shell electrons – valence electrons
Cation – positively charged species/atom
Anion – negatively charged species/atom
Neutral Sodium: 11 protons and 11 electrons
Sodium Cation: 11 protons and 10 electrons
11 (+) – 10(-)= +1
Na+1
Neutral Chlorine: 17 protons and 17 electrons
Chlorine has 7 outer shell electrons
Chlorine Anion: 17 protons and 18 electrons
17(+) – 18(-) = (-)1 net charge
Element
Calcium
Calcium
+2 cation
Potassium
Mass
40.08
40.08
At No.
20
20
P
20
20
N
20
20
E
20
18
39.10
19
19
20
19
Potassium 39.10
+1 cation
Fluorine
19.00
Fluorine - 19.00
1 anion
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19
20
18
9
9
9
9
10
10
9
10
Ionic Bond – true chemical bond that results from the
force of attraction between a cation and an anion
NaCl
Na+1 Cl -1
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Ionic compound (it is NOT a molecule)
Molecules exist because of the formation of Covalent
bonds between the atoms
Covalent bond – true chemical bond that results from
the sharing of valence electrons (outer shell electron)
Polar molecules: unequal electron sharing
Molecules – have shape
Physical properties
Boiling points
Melting points
Density = mass/volume
Solubility
Chemical properties – how reactive is the molecule
Covalent bond
Nonpolar
Polar
Non-Bonding Associations (not true chemical bonds)
*Hydrogen bond: an attraction that exists between
hydrogen and an electronegative element (O, N, Cl)
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Left side of the periodic table: elements are
considered electropositive
Right side of the periodic table: elements are
considered electronegative
Dipole-dipole interactions (stronger)
Dipole: molecule with two “poles”
Van der Waals interactions (weak)
Temporary dipole interactions
See hydrogen bonding with water
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Why high boiling point for water
Water – preferred in living organisms
Liquid at room temperature
BP 100 deg Celsius
MP 0 deg Celsius
Density = 1gm/1cc
Bent geometry
Polar molecule
High heat of vaporization (helps keep body from
overheating)
Good solvent (water dissolve salt)
Solvent + solute (solid, usually ) = Solution
Cohesive molecules (tendency to stick together)
– cohesive forces for water helps to fill blood
vessels
Adhesive molecules
High surface tension
Frozen water (ice ) less dense than liquid
http://en.wikipedia.org/wiki/Water
Water and humans
Sweat/perspiration
Thirst
Digestion
Excretion
Blood
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Dehydrate
Water toxicity
Acids and Bases
H-OH -> H+ + -OH
H+ = hydrogen ions (positively charged/cations)
-
OH = hydroxide ions (negatively charged/anions)
Acidic solution: hydrogen ions are greater than the
hydroxide ions
Basic solution: hydrogen ions are less than the
hydroxide ions
Neutral solution: hydrogen ion concentration is equal
to the hydroxide concentration
Concentration: amount of a substance per unit
volume
pH of solution
pH – measure of acidity
pH = - log10[H+ ]
Acid can release hydrogen ions (cations)
Acidic solutions – high in H (+) ion concentration
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Basic solutions – low in H(+) ion concentration
pH scale
0123456
Very
Acidic
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Neutral
8 9 10 11 12 13 14
Very
Basic
NaOH
Lemon juice
Gastric juice (HCl)
Grapefruit juice, soft drinks
Tomato juice
Human urine
Water
Seawater
Milk magnesia
Household ammonia
Household bleach
Oven cleaner
Buffers: help keep pH within normal limits by taking
up excess hydrogen ions or hydroxide ions.
Blood buffer: H2CO3
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H2CO3
H+
+ HCO3-
H+ + HCO3-
H2CO3
OH- + H2CO3
HCO3- + H2O
Acid rain
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Molecules of Life
Biomacromolecules
Carbohydrates
Lipids
Proteins
Nucleic Acids
Making polymers - synthesis
Removing water – dehydration reaction
Monomer 1 + monomer 2 -> dimer + H2O
Breaking down polymer
Adding water to break up the molecule –
hydrolysis reaction
Polymer + H2O -> Polymer-1 unit
Carbohydrates
Monosaccharides
Glucose – straight chain ->
form a ring
Fructose
CH2O
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Maltose – 2 glucose units bonded together
Disaccharide
Unit 1
Unit 2 Bond
Sucrose (table sugar, cane sugar,
saccharose, or beet sugar)
glucose
fructose α(1→2) sucrase
Lactose (milk sugar)
galactose glucose β(1→4) lactase
Maltose
glucose
glucose α(1→4) maltase
Trehalose
glucose
glucose α(1→1)α trehalase
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Disaccharidase
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Cellobiose
glucose
glucose β(1→4) cellobiase
Polysaccharides – long chains of sugar units
Starch – found in plants: root/ coils into a helix/
branched or unbranched
Glycogen – branched but much more so than
starch/stored in the liver, muscle cells
Cellulose –most abundant organic compound on Earth
- found in plants/forms cable-like fibrils
- cannot be hydrolyzed by most animals
- Sweetness
Natural sugars
Lactose
Maltose
Glucose
Fructose
not as sweet
same sweetness
slightly sweeter
4 times sweeter
Artificial sweetners
Aspartame
Saccharine
Sucralose
Neotame
150 times sweeter
450 times sweeter
600 times sweeter
8000 times sweeter
Splenda – organic compound with chlorine
SugarTwin – saccharin
Sweet n Low - saccharin
Equal – aspartame
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Tongue – 4 parts – sweet, salt, sour, bitter
Refined sugar, raw sugar, honey,
Fiber: High versus Low
Soluble versus insoluble
Lipids
Lipid: not water soluble
Fatty acids
Sterols/steroid
Oils – liquid fat
Fatty acids – saturated (contain no double bonds)
- unsaturated (contain 1 or more double bonds)
- hydrocarbon tail (all CH2)
- polar head (carboxylate group)
FAT = glycerol + long chain carboxylic acid (fatty acid)
Remove water because we are
synthesizing/building up a fat molecule
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Plant derived oils – mostly unsaturated
Animal derived oils – mostly saturated (butter, lard)
Trans fat
Hydrogenated vegetable oil -> veg oil that was
unsaturated become saturated
Nutritional labels
Trans fat
Unsaturated fat
Saturated fat
Phospholipids, waxes and steroids
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Phospholipids – found as a major component of the cell
membrane - > will contribute to the selective properties of
the plasma membrane
Waxes – 1 fatty acid that linked/bonded to an alcohol: more
hydrophobic that fat
Steroids – lipids with a carbon skeleton that forms four fused
rings
Cholesterol
Sex hormones: testosterone, estradiol
Anabolic steroids – variant of male hormone testosterone;
help in muscle build up
As prescription drugs: treat asthma, anemia
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Abused: violent mood swings, depression
High blood pressure, alter cholesterol levels
Shrunken testicles
Reduced sex drive
Infertility
Breast enlargement in men
Masculine characteristics in women
Disrupt menstrual cycle
Stunted growth in teens
THG – tetrahydrogestrinone
Proteins
PROTEINS – POLYMERS OF AMINO ACIDS
Enzymes – synthetic/degration
Keratin – fibrous protein found in hair, skin
Collagen – fibrous (triple helix) found in skin
Elastin – fibrous protein found in skin
Silk – fibrous protein – silk worms/spiders
Actin – fibrous protein found in muscle, found in cells
Myosin – globular protein found in muscle
Hemoglobin – globular protein found in red blood cells
(oxygen binding, carbon dioxide release)
Antibodies – globular
Globular shaped proteins: “round”/spherical
Fibrous shaped proteins: long “fiber”
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Proteins are made from the monomers called amino acids
Amino acids 20
Hydrophilic, Hydrophobic, Acidic, Basic
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Peptide bond formation: dehydration reaction
Protein’s shape: determines the function of the
protein
e.g., enzyme’s active site
Primary structure
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Specific amino acid sequence
Secondary structure – alpha helix (coil)/betapleated sheet (flat)
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Tertiary structure
Quaternary structure
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Linus Pauling – Nobel Prize in Chemistry and Nobel Peace
Prize
Nucleic Acids
DNA (deoxyribonucleic acid) and RNA (ribonucleic acid)
Made up of nucleotides
Nucleotides consist of Nitrogenous bases, phosphate
group and a sugar
Sugar
Strands
Bases
Helix
DNA
deoxyribose
Double stranded
A, G, T, C
yes
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RNA
ribose
Single stranded
A, G, U, C
no
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ATP
ATP functions to have …
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Chemical work ( reactants to products and
reverse:
products to reactants)
Mechanical work ( motion)
Transport work ( molecules across the
membrane)
ATP Cycle
ADP + Pi
ATP
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