Chapter 2: Chemical Basis of Life Vocabulary Flashcards

Vocabulary flashcards covering key concepts, chemical definitions, structures, and imaging techniques from Chapter 2 of Hole's Human Anatomy and Physiology.

Matter

Anything that takes up space and has weight; composed of elements.

Elements

Substances composed of chemically identical atoms.

Bulk elements

Elements required by the body in large amounts.

Trace elements

Elements required by the body in small amounts.

Atoms

Smallest particle of an element.

Proton

Subatomic particle that carries a single positive charge.

Neutron

Subatomic particle that carries no electrical charge.

Electron

Subatomic particle that carries a single negative charge.

Nucleus

Central part of an atom composed of protons and neutrons.

Atomic Number

The number of protons in the nucleus of one atom; equals the number of electrons in the atom.

Atomic Weight

The number of protons plus the number of neutrons in one atom.

Isotopes

Atoms with the same atomic numbers but with different atomic weights (same number of protons and electrons, but a different number of neutrons).

Molecule

Particle formed when two or more atoms chemically combine.

Compound

Particle formed when two or more atoms of different elements chemically combine.

Molecular formulas

Depictions of the elements present and the number of each atom present in a molecule.

Ion

An atom that gains or loses electrons to become stable; an electrically charged atom.

Cation

A positively charged ion formed when an atom loses electrons.

Anion

A negatively charged ion formed when an atom gains electrons.

Ionic Bond

An attraction between a cation and an anion formed when electrons are transferred from one atom to another atom.

Covalent Bond

A chemical bond formed when atoms share electrons.

Polar Molecule

A molecule with a slightly negative end and a slightly positive end, resulting from unequal sharing of electrons in covalent bonds.

Hydrogen Bond

A weak attraction between the positive end of one polar molecule and the negative end of another polar molecule.

Reactants

The starting materials of a chemical reaction, which can be atoms, ions, or molecules.

Products

Substances formed at the end of a chemical reaction.

Synthesis Reaction

A chemical reaction in which a more complex chemical structure is formed ($A + B \rightarrow AB$).

Decomposition Reaction

A chemical reaction in which chemical bonds are broken to form a simpler chemical structure ($AB \rightarrow A + B$).

Exchange Reaction

A chemical reaction in which chemical bonds are broken and new bonds are formed ($AB + CD \rightarrow AD + CB$).

Reversible Reaction

A chemical reaction where the products can change back to the reactants ($A + B \rightleftharpoons AB$).

Electrolytes

Substances that release ions in water.

Acids

Electrolytes that dissociate to release hydrogen ions ($H^+$) in water.

Bases

Substances that release ions that can combine with hydrogen ions ($H^+$).

Salts

Electrolytes formed by the reaction between an acid and a base.

pH scale

A scale that indicates the concentration of hydrogen ions in solution.

Organic molecules

Molecules that contain carbon ($C$) and hydrogen ($H$), are usually larger than inorganic molecules, and dissolve in water and organic liquids.

Inorganic molecules

Molecules that generally do not contain carbon ($C$), are usually smaller than organic molecules, and usually dissociate in water to form ions.

Carbohydrates

Water-soluble organic substances containing carbon, hydrogen, and oxygen with a ratio of $H$ to $O$ close to $2:1$ that provide energy to cells and supply materials to build cell structures.

Lipids

Organic substances soluble in organic solvents and insoluble in water.

Fats (triglycerides)

The most common lipid in the body, used primarily for energy, with building blocks of $1$ glycerol and $3$ fatty acids per molecule.

Phospholipids

Lipid molecules consisting of $1$ glycerol, $2$ fatty acids, and $1$ phosphate per molecule that serve as major components of cell membranes.

Steroids

Lipids composed of four connected rings of carbon.

Proteins

Organic molecules composed of amino acid building blocks held together with peptide bonds.

Nucleic Acids

Organic molecules made of nucleotide building blocks that carry genes and encode amino acid sequences of proteins.

DNA (deoxyribonucleic acid)

A double polynucleotide nucleic acid.

RNA (ribonucleic acid)

A single polynucleotide nucleic acid.

CT Scanning

A clinical imaging technique that uses X-ray emissions to provide 3-D images of internal body parts.

PET Imaging

A clinical technique that uses radioactive isotopes to detect biochemical activity in a specific body part.