Purple Pages Flashcards
element
pure substance that cannot be broken down into simpler substances by ordinary chemical or physical techniques
compound
unit composed of more than one type of atom combined chemically in fixed numbers and ratios
atoms
smallest unit that retains chemical and physical properties of an element
protons
positively charged particle in the nucleus of an atom
neutrons
electrically active cell of the nervous system responsible for controlling behaviour and body functions
electrons
negatively charged particle outside nuclues of atom
atomic number
The number of protons in the nucleus of an atom.
electron shells (valence)
In chemistry and physics, may be thought of as an orbit followed by electrons around an atom’s nucleus. Also known as principal energy level.
ionic bonds
Bond that results from electrical attractions between atoms that have lost or gained electrons.
covalent bonds
Bond formed by electron sharing between atoms.
hydrogen bonds
Noncovalent bond formed by unequal electron sharing between hydrogen atoms and oxygen, nitrogen, or sulfur atoms.
van der waal’s forces
Weak molecular attractions over short distances.
ions
A positively or negatively charged atom.
reactants
The atoms or molecules entering a chemical reaction.
products
An atom or molecule leaving a chemical reaction.
chemical equations
A chemical reaction written in balanced form.
hydration shell
A shell of any chemical species that acts as a solvent and surrounds a solute species. When the solvent is water it is often referred to as a hydration shell or hydration sphere. A classic example is when water molecules form a sphere around a metal ion.
amino acids
A molecule that contains both an amino and a carboxyl group.
chaperone proteins/chaperonins
“Guide” protein that binds temporarily with newly synthesized proteins, directing their conformation toward the correct tertiary structure and inhibiting incorrect arrangements as the new proteins fold.
purines
A type of nitrogenous base with two carbon–nitrogen rings.
pyrimidines
A type of nitrogenous base with one carbon–nitrogen ring.
hydrophilic
Refers to polar molecules that associate readily with water.
hydrophobic
Refers to nonpolar substances that are excluded by water and other polar molecules.
dehydration synthesis
Reaction during which the components of a water molecule are removed, usually as part of the assembly of a larger molecule from smaller subunits. Also referred to as a condensation reaction.
