Fundamentals of Anatomy & Physiology - Chapter 2: The Chemical Level of Organization (Vocabulary Flashcards)

Vocabulary flashcards covering key terms from Chapter 2: The Chemical Level of Organization in Fundamentals of Anatomy & Physiology.

Matter

Anything that takes up space and has mass.

Atom

The basic unit of matter; building blocks that join to form chemicals.

Subatomic particles

Protons, neutrons, and electrons.

Proton

Positive charge; 1 mass unit.

Neutron

Neutral charge; 1 mass unit.

Electron

Negative charge; low mass.

Atomic number

Number of protons; determines chemical properties.

Nucleus

Contains protons and neutrons.

Electron cloud

Spherical region that contains electrons.

Electron shell

Two-dimensional representation of the electron cloud.

Isotopes

Versions of elements based on mass number; mass number = protons + neutrons.

Element

A pure substance composed of atoms of one kind.

Ion

An atom with an electric charge.

Cation

Atom that loses electrons; positively charged.

Anion

Atom that gains electrons; negatively charged.

Ionic bonds

Bonds formed by attractions between cations and anions.

Covalent bonds

Strong bonds involving sharing electrons.

Single covalent bond

Sharing one pair of electrons.

Double covalent bond

Sharing two pairs of electrons.

Triple covalent bond

Sharing three pairs of electrons.

Nonpolar covalent bonds

Equal sharing of electrons; molecules with equal pull.

Polar covalent bonds

Unequal sharing of electrons; form polar molecules (e.g., water).

Hydrogen bonds

Weak polar bonds between adjacent molecules based on partial charges.

Molecule

Two or more atoms joined by strong bonds.

Compound

Two or more atoms of different elements joined by bonds.

Decomposition reaction

Breaks chemical bonds; AB → A + B; hydrolysis AB + H2O → AH + BOH.

Synthesis reaction

Forms chemical bonds; A + B → AB; dehydration synthesis (condensation).

Exchange reaction

Involves decomposition first, then synthesis (AB + CD → AD + CB).

Reversible reaction

At equilibrium; rates are balanced and products/reacants can shift.

Activation energy

Energy required to start a reaction; enzymes lower it.

Enzyme

Protein catalyst that lowers activation energy of reactions.

Active site

Portion of an enzyme where substrates bind.

Substrate

Reactant that binds to an enzyme.

Carbohydrate

Organic molecules with C, H, O; energy and structure.

Monosaccharide

Simple sugars with 3–7 carbon atoms (e.g., glucose, fructose, galactose).

Disaccharide

Two monosaccharides joined by dehydration synthesis (e.g., sucrose, maltose).

Polysaccharide

Polymers of many sugars (e.g., glycogen, starch, cellulose).

Lipid

Hydrophobic molecules; fats, oils, waxes; mainly carbon and hydrogen.

Fatty acid

Long carbon/hydrogen chain with a carboxyl group; may be saturated or unsaturated.

Saturated fatty acid

No double bonds in the hydrocarbon tail.

Unsaturated fatty acid

One or more double bonds; introduces kinks.

Eicosanoid

Signaling molecules derived from arachidonic acid; involved in immunity and inflammation.

Glyceride

Fatty acids attached to a glycerol; includes monoglycerides, diglycerides, triglycerides.

Monoglyceride

Glycerol + one fatty acid.

Diglyceride

Glycerol + two fatty acids.

Triglyceride

Glycerol + three fatty acids; energy storage, insulation, protection.

Steroid

Four-ring carbon structures; cholesterol, hormones, bile salts.

Phospholipid

Diglyceride with a phosphate group; hydrophilic head, hydrophobic tail; major membrane component.

Glycolipid

Diglyceride with a carbohydrate; membrane component.

Protein

Most abundant organic molecule; made of amino acids; 20 amino acids form proteins.

Amino acid

Monomer of proteins; central carbon with amino group, carboxyl group, and R group.

Peptide bond

Dehydration synthesis linking amino acids.

Polypeptide

Long chain of amino acids.

Primary structure

Sequence of amino acids in a polypeptide.

Secondary structure

Hydrogen bonds create alpha helices or beta sheets.

Tertiary structure

Three-dimensional folding of a polypeptide.

Quaternary structure

Assembly of multiple polypeptide chains into a protein complex.

Nucleic acid

Store and process genetic information; DNA and RNA.

DNA

Double-stranded; stores genetic information and directs protein synthesis.

RNA

Single-stranded; mRNA, tRNA, rRNA; involved in protein synthesis.

Nucleotide

Monomer of nucleic acids; contains a sugar, phosphate, and nitrogenous base.

Adenine

Purine base; pairs with thymine in DNA.

Thymine

Pyrimidine base; pairs with adenine in DNA.

Cytosine

Pyrimidine base; pairs with guanine.

Guanine

Purine base; pairs with cytosine.

Uracil

Pyrimidine base; replaces thymine in RNA.

ATP

Adenosine triphosphate; high-energy molecule with three phosphates.

ADP

Adenosine diphosphate; two phosphates.

AMP

Adenosine monophosphate; one phosphate.

Phosphorylation

Addition of a phosphate group to a molecule; creates high-energy bonds.

Buffer

Substance that stabilizes pH; often a weak acid and its salt.

pH

Inverse relationship with hydrogen ion concentration; neutral 7.0; arterial/blood ~7.35–7.45.

Acid

Proton donor; strong acids dissociate completely.

Base

Proton acceptor; strong bases dissociate completely.

Salt

Dissociates into cations and anions other than H+ and OH−.

Hydration sphere

Water molecules surrounding ions to keep them in solution.

Solvent

The liquid in which solutes dissolve.

Solute

Substances dissolved in a solvent.

Solubility

Water is the universal solvent for many substances.

Aqueous solution

Solution in which water is the solvent.