Chapter 2: Basic Chemistry - Vocabulary Flashcards

Vocabulary flashcards covering key terms from Chapter 2: Basic Chemistry, including matter, atoms, bonds, pH, electrolytes, and metabolism.

Atom

The smallest unit of matter that retains the properties of an element; cannot be broken down further without changing the element; atoms bond to form molecules and/or compounds; atoms are electrically neutral.

Element

A substance made of one kind of atom; atoms of the same kind form elements and are electrically neutral.

Molecule

Two or more atoms bonded together.

Compound

A substance formed when atoms of different elements bond.

Proton

Positively charged subatomic particle located in the nucleus.

Neutron

Electrically neutral subatomic particle located in the nucleus.

Electron

Negatively charged subatomic particle orbiting the nucleus in electron shells.

Nucleus

The central core of an atom that contains protons and neutrons.

Electron shell

Regions around the nucleus where electrons reside.

Innermost shell

The first electron shell; stability requires it to hold 2 electrons.

Valence electrons

Electrons in the outermost electron shell that determine bonding and chemical reactivity.

Ion

An atom that has lost or gained electrons, resulting in a net electrical charge.

Cation

An ion with a positive charge (formed when electrons are lost).

Anion

An ion with a negative charge (formed when electrons are gained).

Ionic bond

Bond formed by transfer of electrons from one atom to another, creating ions that attract.

Covalent bond

Bond formed when atoms share electrons to complete outer shells.

Polar covalent bond

Covalent bond where electrons are shared unequally; often results in hydrophilic molecules.

Nonpolar covalent bond

Covalent bond where electrons are shared equally; often hydrophobic.

Water

The most abundant inorganic compound in the body; important in chemical reactions.

Inorganic compound

Substances that usually do not contain carbon and hydrogen (e.g., water, acids, bases, salts).

Organic compound

Substances that contain carbon and hydrogen (e.g., carbohydrates, lipids, proteins, nucleic acids).

Electrolyte

Substances that break into ions when dissolved in water; major functions include hydration, muscle contraction, and nerve impulse transmission.

Salt

A type of electrolyte that dissociates in solution (e.g., NaCl).

Acid

A substance that releases hydrogen ions (H+) when dissolved in water (e.g., hydrochloric acid).

Base

A substance that accepts hydrogen ions (H+) when dissolved in water (e.g., bicarbonate, pancreatic juices, blood, semen, saliva).

pH

A measure of hydrogen ion concentration in solution; 7 is neutral.

Buffer

A substance that resists changes in pH by accepting or releasing H+ to maintain pH in bodily fluids.

Metabolism

The sum of all chemical reactions in the body; includes synthesis (anabolism) and decomposition (catabolism).

Synthesis (anabolism)

Reactions where two or more atoms or molecules combine to form a larger, more complex molecule; dehydration synthesis removes water.

Decomposition (catabolism)

Reactions where a complex molecule is broken down into smaller molecules; hydrolysis; polymers to monomers.

Dehydration synthesis

Building polymers by removing water during monomer linkage.

Hydrolysis

Breaking bonds by adding water to split polymers into monomers.

Hydrophilic

Polar covalent substances that dissolve in water.

Hydrophobic

Nonpolar covalent substances that do not dissolve in water.