BIOL 1020: Chemistry Review and Organic Molecules

Comprehensive vocabulary flashcards covering foundational chemistry concepts, atomic structure, chemical bonding, carbon diversity, isomerism, and polymer biochemistry.

Matter

Anything that takes up space and has mass; all organisms are composed of it, and it is made up of chemical elements.

Element

A substance that cannot be broken down into other substances by chemical reactions. There are $92$ naturally occurring elements.

Compound

A substance composed of two or more different elements joined by chemical bonds, exhibiting emergent characteristics that differ from those of its constituent elements.

Trace Elements

Chemical elements required by an organism in only minute quantities, such as iron ($Fe$) and iodine ($I$).

Atom

The smallest unit of matter that still retains the unique physical and chemical properties of an element.

Atomic Number

The number of protons found in the nucleus of an atom, which equals the number of electrons in a neutral atom.

Mass Number

The sum of the number of protons and neutrons located in the atomic nucleus of an element.

Dalton

The unit of measurement used to express the mass of subatomic particles; protons and neutrons have an almost identical mass close to $1$ dalton.

Isotopes

Different atomic forms of the same element that possess the identical number of protons but differ in their number of neutrons.

Radioactive Isotope

An unstable isotope whose nucleus decays spontaneously, releasing subatomic particles and energy.

Half-Life

The fixed rate of time required for $50\%$ of a parent isotope to decay into its daughter isotope.

Radiometric Dating

A method used to determine the age of rocks or fossils by measuring the ratio of parent to daughter isotopes and calculating how many half-lives have elapsed.

Potential Energy

The energy that matter possesses because of its location or spatial arrangement; in atoms, electrons have potential energy based on their distance from the nucleus.

Valence Electrons

Electrons located in the outermost electron shell (the valence shell) of an atom, which dictate its chemical behavior and bonding capacity.

Orbital

The three-dimensional volume of space where an electron is located $90\%$ of the time; categorized into distinct shapes such as spherical ($s$) and dumbbell-shaped ($p$).

Covalent Bond

A strong chemical bond formed when two atoms share a pair of valence electrons, allowing each atom to complete its valence shell.

Structural Formula

A notation that depicts the arrangement of atoms and covalent bonds within a molecule using lines for shared pairs (for example, $H-H$).

Molecular Formula

An abbreviated chemical formula indicating the type and number of atoms present in a molecule without showing bond arrangements (for example, $H_2$).

Valence

The bonding capacity of an atom, determined by the number of unpaired electrons required to complete its outermost valence shell.

Electronegativity

The attraction of a given atom for the shared electrons within a covalent bond.

Nonpolar Covalent Bond

A covalent bond formed between two atoms whose electronegativity difference is less than $0.5$, resulting in an equal sharing of electrons.

Polar Covalent Bond

A covalent bond between atoms that differ in electronegativity between $0.5$ and $1.7$, causing electrons to be pulled closer to the more electronegative atom and creating partial charges ($\delta+$ and $\delta-$).

Ionic Bond

A chemical bond resulting from the electrostatic attraction between oppositely charged ions, formed when electronegativity differs by more than $1.7$ and an electron is transferred.

Cation

A positively charged ion formed when an atom loses one or more electrons.

Anion

A negatively charged ion formed when an atom gains one or more electrons.

Hydrogen Bond

A weak noncovalent attraction between a hydrogen atom covalently linked to an electronegative atom (usually oxygen or nitrogen) and another electronegative atom.

Van der Waals Interactions

Weak, transient attractions between molecules caused by momentary local charge fluctuations ('hot spots') as electrons move asymmetrically.

Chemical Equilibrium

The state in a reversible chemical reaction where the forward and reverse reactions occur at equal rates, resulting in unchanging relative concentrations of reactants and products.

Hydrocarbons

Organic molecules composed exclusively of carbon and hydrogen atoms, capable of undergoing reactions that release substantial amounts of energy.

Structural Isomers

Compounds that share the identical molecular formula but differ in the covalent arrangement and connectivity of their carbon skeletons.

Cis-Trans Isomers

Compounds with identical covalent partner pairings that differ in their spatial arrangement around an inflexible carbon-carbon double bond.

Enantiomers

Isomers that are nonsuperimposable mirror images of each other due to differing spatial arrangements around an asymmetric carbon atom.

Functional Groups

Specific chemical configurations of atoms that attach to carbon skeletons and participate directly in chemical reactions, giving organic molecules distinctive properties.

Polymer

A large molecule consisting of many similar or identical building blocks linked together by covalent bonds.

Monomer

The smaller, repeating subunit molecule that serves as the building block of a polymer.

Dehydration Reaction

A chemical synthesis reaction in which two monomer molecules become covalently bonded to each other with the concurrent loss of a water molecule ($H_2O$).

Hydrolysis

A chemical cleavage process that breaks covalent bonds in polymers through the addition of a water molecule ($H_2O$), disassembling them into monomers.