Introduction to Biochemistry and Water Properties

Molecule

Two or more atoms chemically bonded together

Compound

A molecule including more than one element

Proton

Nucleus, Positive, ~ 1 amu

Anion

An ion with a negative charge

Atom

the basic unit of matter

Element

a substance consisting of the same type of atoms

Isotopes

Different isotopes of the same element have the same number of protons and a different number of neutrons

Covalent bond

A bond that forms when two atoms share electrons

Hydrogen Bonding

Weak bonds between a hydrogen atom in one molecule and a more electronegative atom of another molecule

Cohesion

The tendency of molecules of the same kind to stick together

Heat capacity

The amount of energy it takes to raise the temperature of the liquid

pH Scale

Ranges from 0 -14, with pH 7 being neutral

Bases

Can taste bitter, sweetish, or salty and can burn skin & eyes

Neutron

Nucleus, Neutral, ~ 1 amu

Electron

Orbiting nucleus, Negative, Negligible

Atomic Mass Unit (AMU)

A unit of mass used to express atomic and molecular weights

Radioactive isotopes

Are useful as tracers and can be damaging to DNA

Ionic bond

An ionic bond happens when two ions with opposite charges attract and are held together

Cation

An ion with a positive charge

Electronegativity

The attraction (pull) for shared electrons

Polar Molecules

Molecules with atoms that have different electronegativities

Nonpolar molecules

Molecules with atoms that have equal electronegativity

Adhesion

The tendency of two different types of molecules to stick together

Capillary action

When liquid flows through narrow spaces without external forces, aided by intermolecular forces

Evaporative cooling

When water evaporates, the molecules with the greatest energy leave the surface, and the liquid that remains cools down

pH

Measures how acidic or basic a solution is

Acids

Often taste sour and can burn skin & eyes