Essay on Chapters 1-5 Notes Ap Biology
Biology- The study of life
A Hierarchy of Organization
Emergent Properties- Novel properties that emerge as each step up the hierarchy of biological order is taken.
Reductionism- Reducing complex systems to simpler components that are more manageable to study.
Cells- The lowest level of structure capable of performing all the activities of life, all organisms are composed of cells which are the basic units of structure and function.
The cell theory- The ability of cells to divide to form new cells is the basis for all reproduction and for the growth and repair of multicellular organisms, including humans.
Two Major Kinds of Cells
Eukaryotic cells- …show more content…
Valence electrons - Electrons in the outermost energy shell (valence shell), chemical properties of an atom depend upon the number of these valence electrons.
Chemical bonds - Attractions that hold atoms together.
Covalent bond - A strong chemical bond between atoms formed by sharing a pair of valence electrons, such as a molecular hydrogen (H2 ).
Structural formula - Formula which represents the atoms and bonding within a molecule
Molecular formula - Formula which indicates the number and type of atoms.
Molecules - Two or more atoms held together by covalent bonds.
Compound - A pure substance composed of two or more elements combined in a fixed ratio. (Compounds can be molecular or ionic)
Electronegativity - Atom's ability to attract and hold electrons. -The more electronegative an atom, the more strongly it attracts shared electrons.
Nonpolar covalent bond - Covalent bond formed by an equal sharing of electrons between atoms.
Polar covalent bond - Covalent bond formed by an unequal sharing of electrons between atoms.
Molecular polarity - the overall polarity of a molecule.
Ion - Charged atom or group of atoms.
Anion - An atom that has gained one or more electrons from another atom and has become negatively charged; a negatively charged ion.
Cation - An atom