Unit 2 Vocabulary Flashcards
Matter
Anything that takes up space and has mass
Element
Any substance that cannot be broken down to any other substance
Compound
A substance consisting of two or more elements in a fixed ratio
Trace elements
Elements indispensable for life but required in extremely minute amounts
Neutron
An electrically neutral particle (a particle having no electrical charge), found in the nucleus of an atom
Proton
A subatomic particle with a single positive electrical charge, found in the nucleus of an atom
Electron
A subatomic particle with a single negative charge. One or more electrons move around the nucleus of an atom
Nucleus
(1) An atom’s central core, containing protons and neutrons. (2) The chromosome containing organelle of a eukaryotic cell. (3) A cluster of neurons.
Atomic number
The number of protons in the nucleus of an atom, unique for each element and designated by a subscript to the left of the elemental symbol
Mass number
The sum of the number of protons and neutrons in an atom’s nucleus
Atomic mass
The total mass of an atom, which is the mass in grams of one mole of the atom
Isotope
One of several atomic forms of an element, each containing a different number of neutrons and thus differing in atomic mass
Valence electrons
Electrons in the outermost electron shell
Covalent bond
A type of strong chemical bond in which two atoms share one or more pairs of valence electrons
Ionic bond
A chemical bond resulting from the attraction between oppositely charged ions
Polar bond
A covalent bond between atoms that differ in electronegativity. The shared electrons are pulled closer to the more electronegative atom, make it slightly negative and the other atom slightly positive
Nonpolar bond
A type of covalent bond in which electrons are shared equally between two atoms of similar electronegativity
Hydrogen bond
A type of weak chemical bond formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule
Electronegativity
The attraction of an atom for the electrons of a covalent bond
Ion
An atom that has gained or lost electrons, thus acquiring a charge
Van der Waals interactions
Weak attractions between molecules or parts of molecules that are brought about by localized charge fluctuations
Reactants
Staring materials in a chemical reaction
Products
Ending materials in a chemical reaction
Cohesion
The binding together of like molecules, often by hydrogen bonds
Adhesion
The attraction between different kinds of molecules
Surface tension
A measure of how difficult it is to stretch or break the surface of a liquid. Water has a high surface tension because of the hydrogen bonding of surface molecules
Specific heat
The amount of heat that must be absorbed or lost for 1 g of a substance to change its temperature by 1 degree C
Solution
A liquid that is a homogeneous mixture of two or more substances
Solvent
The dissolving agent of a solution. Water is the most versatile solvent known. I’m
Solute
A substance that is dissolved in a solution
Hydrophilic
Having an affinity for water
Hydrophobic
Having an aversion to water; tending to coalesce and form droplets in water
Acid
A substance that increases the hydrogen ion concentration of a solution
Base
A substance that reduces the hydrogen ion concentration of a solution
pH
A measure of hydrogen ion concentration equal to -log[H+] and ranging in value from 0 to 14
Buffers
Substances that consist of acid and base form in a solution that minimizes changes in pH when extraneous acids or bases are added to the solution
Organic chemistry
The study of carbon compounds (organic compounds)
Hydrocarbons
Organic molecules consisting only of carbon and hydrogen
Functional groups
Specific configurations of atoms commonly attached to the carbon skeletons of organic molecules and usually involved in chemical reactions
Macromolecule
A giant molecule formed by the joining of smaller molecules, usually by a condensation reaction. Polysaccharides, proteins, and nucleic acids are macromolecules
Polymer
A long molecule consisting of many similar or identical monomers linked together
Monomer
The subunit that serves as the building block of a polymer
Dehydration synthesis (for dehydration reaction)
A chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule
Hydrolysis
A chemical process that lyses, or splits, molecules by the addition of water
Carbohydrate (mono-, poly-, disaccharides)
A sugar (monosaccharide) or one of its dimers (disaccharides) or polymers (polysaccharides)
Starch
A storage of polysaccharide in plants consisting entirely of glucose
Glycogen
An extensively beached glucose storage polysaccharide found in the liver and muscle of animals; the animal equivalent of starch
Cellulose
A structural polysaccharide of cell walls, consisting of glucose monomers joined by B-1, 4-glycosidic linkages
Fatty acid
A long carbon chain carboxylic acid. Fatty acids vary in length and in the number and location of double bonds; three fatty acids linked to a glycerol molecule form fat
Triglyceride
A lipid molecule made up of one unit of glycerol and three fatty acids
Saturated fatty acid
A fatty acid in which all carbons in the hydrocarbon tail are connected by single bonds, thus maximizing the number of hydrogen atoms that can attach to the carbon skeleton
Unsaturated fatty acid
A fatty acid possessing one or more double bonds between the carbons in the hydrocarbon tail. Such bonding reduces the number of hydrogen atoms attached to the carbon skeleton
Phospholipid
A molecule that is a constituent of the inner bilayer of biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail
Cholesterol
A steroid that forms an essential component of animal cell membranes and acts as a precursor molecule for the synthesis of other biologically important steroids
Enzyme
A protein serving as a catalyst, a chemical agent that changes the rate of a reaction without being consumed by the reaction
Catalyst
A chemical agent that changes the rate of a reaction without being consumed by the reaction
Protein
A three dimensional biological polymer constructed from a set of 20 different monomers called amino acids
Amino acids
Organic molecules possessing both carboxyl and amino groups. Amino acid serve as the monomers of proteins
Denaturation
In proteins a process in which a protein unravels and loses its native confirmation thereby becoming biologically and active. In DNA the separation of the two strands of the double helix. Do you naturalization occurs under extreme conditions of pH, salt concentration and temperature
