Chapter 21: General Chemistry of Life Notes

A set of vocabulary flashcards key concepts from general chemistry notes, including atomic structure, chemical bonding, properties of water, acids and bases, and organic polymerization.

Matter

Anything that has mass and occupies space.

Element

A fundamental unit of matter consisting entirely of one type of atom.

Six Major Elements in the Body

Carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur.

Four Major Elements in Living Matter

Carbon, hydrogen, nitrogen, and oxygen.

Subatomic Particles

The three main constituents of an atom: protons (positively charged, located in the nucleus), neutrons (neutral, located in the nucleus), and electrons (negatively charged, found in electron shells around the nucleus).

Atomic Number

The number of protons in an atom.

Mass Number

The sum of the number of protons and neutrons in an atom.

Isotopes

Atoms of the same element that have different numbers of neutrons.

Radioactive Isotopes

Unstable isotopes that decay over time.

Valence Shell

The outermost electron shell of an atom.

Valency

The number of unpaired electrons in the outer shell of an atom.

Electronegativity

The tendency of an atom to attract electrons, determined by the number of protons and the distance of the valence shell from the nucleus.

Covalent Bond

A chemical bond formed when atoms share electrons.

Nonpolar Covalent Bond

A covalent bond where electrons are shared equally.

Polar Covalent Bond

A covalent bond where electrons are shared unequally, producing partial charges.

Ionic Bond

A bond formed when an electron is completely transferred from one atom to another by electrical attraction.

Cation

A positively charged ion formed when an atom loses an electron.

Anion

A negatively charged ion formed when an atom gains an electron.

Hydrogen Bond

An attraction between atoms or molecules with partial charges.

Van der Waals Interactions

Weak electrical attractions caused by the movement of electrons that create momentary asymmetry.

Cohesion

Attraction between molecules of the same type, such as water molecules held together by hydrogen bonds.

Adhesion

Attraction between different molecules, such as water adhering to a surface.

Surface Tension

A cohesive force at the surface of water caused by attraction between water molecules that minimizes surface area.

Hydrophilic

Water-loving; describes substances, including ions and polar molecules, that interact with water.

Hydrophobic

Water-fearing; describes uncharged, nonpolar substances that do not dissolve in water.

Acid

A substance that gives up protons and raises the hydronium concentration in solution ($\text{pH} < 7$).

Base

A substance that acquires protons and lowers the hydronium concentration in solution ($\text{pH} > 7$).

pH Scale

A logarithmic measurement defined by $\text{pH} = -\log_{10}([\text{H}^+])$, where a value of $7$ indicates neutral, below $7$ indicates acidic, and above $7$ indicates basic.

Buffer

A compound or system that minimizes changes in pH and helps maintain relatively constant conditions.

Bicarbonate Buffer System

An important physiological buffer system in the body involving carbonic acid and bicarbonate.

Functional Groups

Specific chemical groups attached to a carbon skeleton that define the chemical behavior of organic molecules.

Amino Group

A functional group that generally attracts protons and acts as a base.

Carboxyl Group

A functional group that generally gives up a proton and acts as an acid.

Sulfhydryl Group

A functional group ($-\text{SH}$) that can link together through disulfide bonds ($\text{S}-\text{S}$).

Monomer

A smaller molecular subunit that can join with other monomers to form a large molecule.

Polymer

A large molecule formed by joining many monomers together.

Polymerization

The process of chemically linking monomers to form a polymer.

Dehydration Synthesis (Condensation)

A reaction that joins monomers into a polymer by removing water and requiring energy.

Hydrolysis

A reaction in which water is added to break covalent bonds between monomers, separating them from a polymer and releasing energy.