Honors Biology - Biochemistry Unit

matter

Anything that occupies space and has mass.

element

Pure substance that cannot be broken down chemically into simpler kinds of matter.

compound

A pure substance that is made up of atoms of two or more elements.

chemical reaction

Any process in which a chemical change occurs.

reactants

Shown on the left side of the equation; starting materials.

products

Shown on the right side of the equation; ending materials.

acid

Compound that has a pH below 7.

base

Compound that has a pH above 7.

neutral

Substance with a pH of exactly 7.

pH scale

0 to 14 scale that measures the acidity or basicity of substances; each step on the scale represents a tenfold change in acidity or basicity.

cohesion

Attractive force between particles of the same kind (such as water molecules "sticking" to other water molecules).

adhesion

Attractive force between unlike substances (such as water molecules sticking to other substances or surfaces).

surface tension

Results from cohesion of water molecules on the surface of a body of water; allows some organisms to walk on water.

monomer

Building Block;" smaller compound which must be joined together with other small compounds to build larger molecules.

polymer

Molecule consisting of linked units or building blocks (monomers).

macromolecule

VERY large polymer that typically consists of thousands of units.

polymerization

The process by which large compounds are constructed by joining together smaller compounds.

dehydration synthesis

Two or more monomers are combined to form larger molecules; water is lost during this polymerization reaction.

hydrolysis

A molecule of water is added to break apart the bond between two or more joined monomers; occurs when large molecules are split apart.

ATP

Stores and transports energy from one part of the cell to another.

carbohydrate

Known as "sugars and starches;" built from monosaccharides.

monosaccharide

Simplest carbohydrate; used to build bigger carbohydrates; examples include glucose, fructose, and galactose.

disaccharide

Double sugar" formed by joining two monosaccharides; examples include sucrose (table sugar), lactose, and maltose.

polysaccharide

Complex carbohydrate formed by joining three or more monosaccharides; examples include starch, glycogen, and cellulose.

protein

Built from amino acids joined by peptide bonds; these molecules have many roles in the cell and are generally considered to be "workers.

enzyme

A type of protein that speeds up the rate of a chemical reaction (a catalyst).

lipid

Built from one glycerol and three fatty acids; substances are typically oily or waxy; used for energy storage and cell membranes.

saturated fat

Fat that contains all single bonds; contains maximum number of hydrogen atoms and forms straight chains. (Solid at room temperature.)

unsaturated fat

Fat that contains one or more double bonds; does not contain maximum number of hydrogen atoms and forms "kinked" chains. (Liquid at room temperature.)

nucleic acid

Built from nucleotides; store and transmit genetic information; examples include DNA and RNA.