General Chemistry and Biological Molecules Lecture Review

Vocabulary practice flashcards covering key definitions, chemical bonding, atomic properties, solution chemistry, and organic biological macromolecules from the lecture material.

Dalton

A unit of mass assigned a general value of 1, corresponding to the mass of one proton ($1.007$) or one neutron ($1.008$).

Atomic Mass

The total number of protons and neutrons in the nucleus of an atom, representing the average mass of all stable atoms of an element in daltons.

Atomic Number

The number of protons in the nucleus of an atom, which directly corresponds to the number of electrons in a neutral atom.

Isotope

An atom of an element containing additional neutrons in its nucleus, giving it a different mass while retaining the same chemical properties.

Valence Electrons

Electrons located in the outermost shell (or shell adjacent to it) that are available to interact chemically and form bonds.

Octet Rule

The chemical principle stating that atoms interact to achieve a stable energy configuration, typically with 8 electrons in their outer shell.

Electronegativity

A measure of an atom's ability to attract an electron from another element to complete its outer shell octet.

Anion

A negatively charged atom or molecule that has acquired one or more electrons.

Cation

A positively charged atom or molecule that has donated one or more electrons, leaving an excess of protons.

Ionic Bond

A chemical bond created when one atom completely gives up an electron to another atom that acquires and retains it.

Covalent Bond

A chemical bond formed by the sharing of a pair of electrons between two atoms, with each atom donating one electron to the shared pair.

Hydrogen Bond

An attraction between the single proton of a hydrogen atom covalently bound to an electronegative atom (like $N$, $O$, or $F$) and the electron field of another electronegative atom.

Polar Molecules

Molecules that possess an uneven distribution of electrons across their structure, resulting in partial positive and negative charges.

Van Der Waal Forces

Weak attractions between the electron field of one atom and the nucleus of a nearby atom, influencing molecular spacing and hydrophobic interactions.

Activation Energy

The initial energy input required to overcome the energy barrier and allow a chemical reaction to occur.

Catalyst

A substance, such as an enzyme, that speeds up a chemical reaction by providing an alternate pathway that lowers the required activation energy.

Apoenzyme

The protein portion of an enzyme that requires a nonprotein cofactor to function properly.

Cofactor

The nonprotein component of an enzyme, such as a metal ion or vitamin, necessary for catalytic activity.

Hydrophobic

Describing nonpolar molecules with an even electron distribution that are poorly soluble and do not dissolve in water.

Hydrophilic

Describing polar molecules or ions that are attracted to water and dissolve or suspend readily in an aqueous solution.

Mole

An amount of a substance equal to its molecular weight weighed out in grams.

Avogadro's Number

The number of molecules present in one mole of any substance, equal to $6.02 \times 10^{23}$.

Acid

A substance that donates hydrogen ions ($H^+$ or $H_3O^+$) to an aqueous solution.

Base

A substance that donates hydroxyl ions ($OH^-$) to an aqueous solution.

Buffer

A salt of a weak acid or base that resists changes in pH by exchanging ions and absorbing added $H^+$ or $OH^-$ ions.

Isomers

Molecules that share the same molecular formula but have different structural configurations (such as glucose and fructose, which are both $C_6H_{12}O_6$).

Dehydration Synthesis

A chemical reaction that links monomer subunits into polymers by removing a molecule of water.

Hydrolysis

A chemical process that breaks down polymers into monomer subunits through the addition of water.

Glycogen

A large polysaccharide polymer composed of glucose units that serves as the primary storage form of sugar in animal liver and muscle tissue.

Triglyceride

A lipid molecule composed of glycerol bonded to three fatty acid chains, serving as the storage form of fat in adipocytes.

Phospholipid

A lipid molecule consisting of glycerol, two fatty acids, and a phosphate group, forming the primary component of cell membrane bilayers.

Peptide Bond

A covalent bond formed between two amino acids during a dehydration synthesis reaction.

Nucleoside

A molecular structure consisting of a nitrogenous base attached to a sugar (such as ribose or deoxyribose).

Nucleotide

A monomer unit of nucleic acids composed of a nitrogenous base, a sugar, and one or more phosphate groups.

ATP (Adenosine Triphosphate)

A nucleotide compound consisting of adenine, ribose, and three phosphate groups containing high-energy bonds used to power cellular processes.