BIOLOGY
by Miller & Levine
[complete Table of Contents]
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Periodic
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Chapter 2
The
Chemistry of Life
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Section 2-1: The Nature
of Matter
The subatomic
particles that make up atoms are protons, neutrons, and electrons.
Because they have the same number of protons, all isotopes of an element
have the same chemical properties.
The main types
of chemical bonds are covalent bonds and ionic bonds.
Section 2-2: Properties of Water
A water molecule is polar, because there
is an uneven distribution of electrons between the oxygen and hydrogen
atoms.
Acidic solutions contain higher concentrations
of H+ ions than pure water and have pH values below 7.
Basic, or alkaline, solutions contain
lower concentrations of H+ ions than pure water and have pH values above
7.
Section 2-3: Carbon Compounds
Four groups of carbon compounds found
in living things are carbohydrates, lipids, nucleic acids, and protein.
Living things use carbohydrates as their
main source of energy. Plants and some animals also use carbohydrates
for structural purposes.
Lipids can be used to store energy. Some
lipids are important parts of biological membranes and waterproof coverings.
Nucleic acids store and transmit hereditary,
or genetic, information.
Some proteins control the rate of reactions
and regulate cell processes. Some proteins build tissues such as bone
and muscle. Others transport materials or help to fight disease.
Section 2-4: Chemical Reactions and Enzymes
Chemical reactions always involve the
breaking of bonds in reactants and the formation of new bonds in products.
Chemical reactions that release energy
often occur spontaneously. Chemical reactions that absorb energy will
not occur without a source of energy.
Cells use enzymes to speed up chemical
reactions that take place in cells.
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