Chemical Foundation of Life and Water Properties Flashcards

Vocabulary flashcards covering atomic structure, chemical bonding, water properties, pH, and the four major biological macromolecules.

Atom

The smallest unit of matter that retains all the chemical properties of the element.

Nucleus

The center of an atom, made of protons ($+$) and neutrons ($0$).

Proton

A particle located in the nucleus with a charge of $+1$ and a mass of $1\,amu$.

Neutron

A particle located in the nucleus with a charge of $0$ and a mass of $1\,amu$.

Electron

A particle that travels in orbitals around the nucleus with a charge of $-1$, having negligible mass.

Atomic Number

The value determined by the number of protons in an element's atom.

Isotope

Different forms of an element that have the same number of protons but a different number of neutrons.

Mass Number

The total value determined by adding protons and neutrons together.

Atomic Mass

The calculated mean of all an element's isotopes; for example, Chlorine is $35.45$.

Molecule

Two or more atoms chemically bonded together.

Reactants

The substances going into a chemical reaction, located on the left side of the arrow in a chemical equation.

Products

The substances formed by a chemical reaction, located on the right side of the arrow in a chemical equation.

Law of Conservation of Mass

The principle that mass is not created or destroyed in chemical reactions, requiring equations to remain balanced.

Compound

A molecule that contains atoms of more than one element.

Ions

Atoms that alter their number of electrons to fill their outermost shell, becoming more stable but losing electrical neutrality.

Cations

Ions that have a positive charge resulting from losing electrons.

Anions

Ions that have a negative charge resulting from gaining electrons.

Ionic Bonds

Bonds formed between ions with opposite charges, such as positive sodium and negative chloride forming Sodium chloride.

Covalent Bonds

Bonds created when two atoms share electrons; these are stronger and more common in living things than ionic bonds.

Polar Covalent Bond

A bond where electrons are shared unevenly because they are attracted more to one atom than the other, as seen in water.

Non-polar Covalent Bond

A bond where electrons are shared evenly between atoms, such as in molecular oxygen ($O_2$).

Hydrogen Bond

Weak and easily broken bonds that form when the slightly positive charge of hydrogen in a molecule binds to the slightly negative charge of another molecule.

Hydrophilic

Polar substances that dissolve readily in water.

Hydrophobic

Non-polar substances, such as oil, that do not dissolve in water.

Specific Heat

The amount of heat (energy) a gram of a substance must absorb or lose to change its temperature by $1^\circ C$.

Heat of Vaporization

The amount of energy required to change one gram of liquid to a gas, which for water happens at $100^\circ C$ ($212^\circ F$).

Solvent

A substance capable of dissolving other polar molecules and ionic compounds.

Cohesion

The attraction of water molecules to each other due to hydrogen bonding, creating high surface tension.

Surface Tension

The ability of a substance to withstand rupturing when placed under stress.

Adhesion

The attraction between water molecules and other molecules, responsible for capillary action in glass beakers.

pH Scale

A scale from $0$ to $14$ that measures the hydrogen ion ($H^+$) concentration of a solution.

Acid

A substance with a pH from $0$ to $6.99$ that increases hydrogen ions ($H^+$) in a solution.

Base

A substance with a pH from $7.01$ to $14$ that increases hydroxide ions ($OH^-$) or other ions that bond with free $H^+$.

Buffer

Substances that readily absorb $H^+$ or $OH^-$ ions to help keep the body's pH within a narrow range.

Macromolecule

A subset of organic molecules containing carbon that is important to life, including liquids, solids, or gases.

Hydrocarbons

Organic molecules consisting only of carbon and hydrogen.

Isomer

Molecules with the same chemical formula but a different structure and placement of atoms or bonds.

Functional Groups

Groups of atoms found along the carbon backbone of macromolecules that supply specific chemical properties.

Carbohydrates

Macromolecules used for structural purposes and short-term energy storage.

Lipids

Water-insoluble macromolecules used for long-term energy storage, insulation, and membranes.

Proteins

Macromolecules that catalyze reactions as enzymes, provide structure, and aid in muscle contraction; their complex 3D structure is essential for function.

Nucleic Acids

DNA and RNA, which encode the information necessary to make proteins.