Download Intro Biochemistry/Ecology

Chapter 2
Essential Learning Keys
We are combining our biochemistry unit and introductory ecology units into one big topic
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.
Chapter 3
Essential Learning Keys
Section 3-2: Energy Flow
Sunlight is the main energy source for life on Earth. In a few ecosystems, some organisms rely on the
energy stored in inorganic chemical compounds.
Energy flows through an ecosystem in one direction, from the sun or inorganic compounds to
autotrophs (producers) and then to various heterotrophs (consumers).
Only about 10 percent of the energy available within one trophic level is transferred to organisms at
the next trophic level.