BIOLOGY 101 –
REVIEWER
Atom – is the smallest basic unit of matter. An element is one type of atom
Parts of an atom:
protons, neutrons, and electrons
Compound – made of atoms of different elements bonded together
Ion – an atom that has gained or lost one or more electrons
Isotopes – atoms with a different number of neutrons
Ionic bond – forms between oppositely charged ions
Covalent bond – forms when atoms share a pair of electrons
Hydrogen bond – forms between slightly positive hydrogen atoms and slightly negative atoms
Solution – formed when one substance dissolves in another. It is a homogenous mixture
Solvent – dissolves other substances
Solute – dissolves in a solvent
solution
Carbon-based molecules are the foundation of life.
* Carbon forms covalent bonds with up to four other atoms.
* Carbon-based molecules are made of small subunits bonded together.
There are four main types of carbon-based molecules found in living things
* Carbohydrates – made of carbon, hydrogen, and oxygen. Includes sugars and starches (monomer: simple sugars)
* Lipids – nonpolar molecules that include fats, oils, and cholesterol (monomer: fatty acid)
* Proteins – polymers of amino acids
* Nucleic acids – polymers of nucleotides. Nucleotides are made of sugar, phosphate, and a nitrogen base
Life is a series of chemical reactions
* Bonds break and form during chemical reactions
* Bond energy – amount of energy that breaks a bond. Energy is added to break bonds.Energy is released when bonds form.
* Activation energy – amount of energy that needs to be absorbed to start a chemical reaction.
* Catalysts – substances that speed up chemical reactions
* Enzymes – catalysts in living things. Needed for almost all processes. Most enzymes are proteins
3 Principles of Cell Theory
* All organisms are made of cells
* All existing cells are produced by other living cells
* The cell is the most basic unit of...