Matter and energy and life

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Transcript Matter and energy and life

Matter and Energy and Life
Donald Winslow
14 January 2014
Matter & energy
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Matter
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Composed of particles, has mass
Energy
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The ability to do work, involves forces that affect
position & movement of particles.
Kinetic energy, potential energy, heat, light,
electromagnetic radiation.
Subatomic particles
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Atomic nucleus composed of protons & neutrons;
electrons orbit nucleus.
Protons
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Electrons
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Positive (+) charge, ~1 atomic mass unit
Electric (-) charge, ~0 atomic mass units
Potential energy of electron increases with increasing
distance from nucleus.
Neutrons
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No charge, ~1 atomic mass unit
Matter & energy
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Matter
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Composed of particles, has mass
Energy
–
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The ability to do work, involves forces that
affect position & movement of particles.
Kinetic energy, potential energy, heat, light,
electromagnetic radiation.
Subatomic particles
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Atomic nucleus composed of protons &
neutrons; electrons orbit nucleus.
Protons
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Electrons
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Positive (+) charge, ~1 atomic mass unit
Electric (-) charge, ~0 atomic mass units
Potential energy of electron increases with
increasing distance from nucleus.
Neutrons
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No charge, ~1 atomic mass unit
Elements & atoms
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Atomic symbols
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Atomic numbers
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C, H, N, O, P, S, etc.
Number of protons in nucleus
Periodic table of the elements
Isotopes
– 12C
& 14C, radiation
Atoms can be
combined to form molecules.
Chemical reactions result in
exchange of atoms between
molecules, synthesis of large
molecules from small molecules,
or division of large molecules into
small molecules.
Elements & compounds
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An element contains only one kind of
atom.
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Examples: Au, O2
A compound contains multiple kinds of
atoms.
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Examples: H2O, CO2
Chemical bonds
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Ionic bonds
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Relation to salts
Covalent bonds
Polar covalent bonds
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Hydrogen bonds
Properties of water
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High heat capacity, high heat of
vaporization
Solvent
Cohesion & adhesion
Ice is less dense than water
Hydrogen ion concentration is measured
by pH
Acids, bases, & buffers
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An acidic solution has a high H+ concentration &
therefore a low pH.
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A basic (alkaline) solution has a low H+
concentration & therefore a high pH.
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vinegar, citric acid, ascorbic acid, HCl, H2SO4
sodium bicarbonate (NaHCO3), antacid, NaOH
A buffer solution contains a compound that
maintains the pH within a narrow range by
binding excess H+ and OH- ions.
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Examples: carbonic acid (H2CO3), NaHCO3
Organic molecules
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Lipids
Carbohydrates
Amino acids & proteins
Nucleic acids
Lipids
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Variable structure
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Lots of H & C; not much O or N
Not water soluble
Functions in energy storage, membranes,
chemical messengers, etc.
Fatty acids, phospholipids, steroids,
cholesterol, waxes, oils
Carbohydrates
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Polysaccharides are polymers of
monosaccharides (monomeric sugars).
Function in energy storage & transfer,
structural features such as plant cell walls
Examples: glucose, fructose, sucrose
(table sugar), lactose, starch, glycogen
Proteins
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Proteins are polypeptides, often modified
to form complex shapes.
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A polypeptide is a polymer of amino acids,
connected by peptide bonds.
Function as enzymes (catalyzing chemical
reactions), structural proteins, hormones,
antibodies, etc.
Examples: amylase, keratin, insulin
Nucleic acids
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Nucleic acids are polymers of nucleotides.
Function in heredity; direct cellular
metabolism, development, etc.
Examples: deoxyribonucleic acid (DNA),
ribonucleic acid (RNA)
Molecular shape is important to
biological function
Properties of living things
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Growth, development, reproduction
Need energy & materials for metabolism
Composed of cells
Organized
Communication of information
Adaptation
Genes direct development, etc.
Biological hierarchy
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Cell
Tissue
Organ
Organ system
Organism
Population
Community
Nine-banded armadillo
Ecological hierarchy
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Organism
Population
Community
Ecosystem
Landscape
Biome
Biosphere
Agricultural corridor within forested
landscape in southern Indiana.
Taxonomic hierarchy
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Domain
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Kingdom
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Phylum
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Class
● Order
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Family
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Genus
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Species