Bio93 - Lecture 2 Vocab - Wood/Mattheos/Green

Bio93 - Atoms, Molecules and Water

Chemical bonds

Forces of attraction that hold atoms together in molecules or compounds, arising from the sharing or transfer of electrons.

Hydrogen bonds

A weak type of attraction between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom, important in stabilizing molecular structures.

Covalent bonds

A type of chemical bond formed when two atoms share one or more pairs of electrons, typically occurring between nonmetal atoms.

Ionic bonds

A type of chemical bond formed through the electrostatic attraction between positively and negatively charged ions, usually occurring between metal and nonmetal atoms.

Atom

Smallest unit of matter that retains the properties of an element

Elements

Can’t be broken down into other substances by a chemical reaction - composed of only 1 atom

Molecules

A group of two or more atoms held together by chemical bonds

Compound

A pure substance made of two or more different elements joined together by chemical bonds in a fixed ratio

Hydration shell

A structured layer of water molecules that surrounds a solute particle- such as an ion, polar molecule, or biomolecule - when it is dissolved in water

Hydrophobic

A physical property of a substance that repels or fails to mix with water

Hydrophilic

Water-loving

Solvent

A substance- usually a liquid- that dissolves another substance (called a solute) to form a uniform mixture known as a solution.

Solute

The substance that gets dissolved in a solution

Solution

A uniform, single-phase mixture composed of two or more substances

pH

A scale from 0 to 14 that measures how acidic or basic a water-based liquid is.

Hydrogen ion

A positively charged particle formed when a hydrogen atom loses its single electron, leaving behind a bare proton.

Hydroxide ion

A negative charged diatomic ion with the chemical formula OH-, consisting of one oxygen atom covalently bonded to one hydrogen atom.

Buffers

A water-based solution that resists changes in pH when small amounts of an acid or a base are added.