Fundamentals of Anatomy & Physiology - Chapter 2 Vocabulary

Flashcards for Anatomy & Physiology Chapter 2

Chemistry

The science that deals with the structure of matter.

Matter

Anything that takes up space and has mass.

Atom

The smallest stable unit of matter.

Protons

Positively charged subatomic particles.

Neutrons (n)

Neutral subatomic particles.

Electrons

Negatively charged subatomic particles.

Atomic number

The number of protons in an atom.

Electron cloud

Area around the nucleus that contains electrons.

Electron shell

Two-dimensional representation of an electron cloud.

Element

A pure substance composed of atoms of one kind.

Isotopes

Versions of an element that have different numbers of neutrons.

Mass number

The number of protons plus the number of neutrons of an atom.

Radioisotopes

Isotopes that have unstable or radioactive nuclei.

Half-life

The time required for half of a given amount of isotope to decay.

Atomic weight

An average of the different atomic masses and proportions of different isotopes.

Atomic mass

The actual mass of an atom, taking into account the masses of its protons, neutrons and electrons

Mole (mol)

A specific quantity that has a weight in grams equal to the atomic weight of the element.

Valence shell

The outermost shell, and the number of electrons in this shell determines the chemical properties of an element.

Inert elements

Have a full valence shell and are not reactive.

Chemical bonds

Hold participating atoms together once the reaction has ended.

Molecule

Two or more atoms joined by shared electrons.

Compound

Two or more atoms of different elements.

Ionic bonds

Bonds created by the attractions between negative and positive ions.

Ion

An atom with an electric charge.

Covalent bonds

Bonds created when atoms share electrons.

Nonpolar covalent bonds

Equal sharing of electrons between two atoms.

Polar covalent bonds

Unequal sharing of electrons between two atoms.

Hydrogen bonds

Weak electrical attractions between the partial positive charge of a hydrogen atom in a polar covalent bond and the partial negative charge of an atom of oxygen, nitrogen or fluorine in another polar covalent bond.

Solid

Has constant volume and shape.

Liquid

Has constant volume but no fixed shape.

Gas

No constant volume and no fixed shape.

Chemical reactions

Result in the formation of new bonds or the breaking of existing bonds.

Reactants

The reacting substances that enter the reaction.

Products

The resulting substances at the end of the reaction.

Metabolism

All chemical reactions that are occurring in the cells and tissues of the body at any given time.

Work

The movement of an object or a change in the physical structure of matter.

Energy

The capacity to do work.

Kinetic energy

The energy of motion.

Potential energy

Stored energy an object possesses because of its position or its physical or chemical structure.

Decomposition reactions

Break molecules into smaller fragments.

Synthesis reactions

Assemble larger molecules from smaller molecules.

Exchange reactions

Rearrange existing components of molecules into new products.

Reversible reactions

Many important biological reactions are freely reversible.

Biochemical reactions

Reactions that happen in living organisms.

Activation energy

Amount of energy needed to start the reaction.

Enzymes

Catalysts that lower the activation energy of reactions.

Exergonic reactions

The amount of energy released is greater than the activation energy, so net release of energy.

Endergonic reactions

The activation energy is more than the energy produced, so the reaction absorbs energy.

Nutrients

Substances from food that are necessary for normal physiological function.

Metabolites

Substances that are involved in metabolism.

Inorganic compounds

Do not contain carbon in bonds to hydrogen as primary structural component.

Organic compounds

Contain carbon in bonds to hydrogen

Water

The most important substance in the body.

Solution

Uniform mixture of two or more substances.

Solute

The dissolved substance.

Solvent

The liquid in which the solutes are distributed.

Aqueous solution

Solution in which water is the solvent.

Heat capacity

Quantity of heat required to raise the temperature of a unit mass of a substance by 1°C

Ionization

Dissociation into ions.

Electrolytes

Soluble inorganic substances whose ions conduct electricity in solution.

Hydrophilic

Interact readily with water.

Hydrophobic

Do not interact readily with water.

Colloid

A solution containing dispersed proteins or other large molecules

Suspension

Contains large particles in solution, but if undisturbed the particles will settle out of solution

pH

The negative logarithm of the hydrogen ion concentration of a solution in moles per liter.

Acid (proton donor)

Any solute that adds hydrogen ions to a solution.

Base (proton acceptor)

Any solute that removes hydrogen ions from a solution.

Salt

Ionic compound that dissociates in water into cations and anions other than hydrogen ions and hydroxide ions.

Buffers

Compounds that stabilize the pH of solutions.