Chapter 2: Basic Chemistry (Essentials of Human Anatomy & Physiology)

Vocabulary flashcards covering essential terms from Chapter 2: Basic Chemistry (matter, energy, atoms, bonds, molecules, acids/bases, pH, organic/inorganic compounds, carbohydrates, lipids, proteins, nucleic acids, and ATP).

Matter

Anything that occupies space and has mass.

States of Matter

Solid: definite shape and volume; Liquid: definite volume; shape of container; Gas: neither definite shape nor volume.

Physical Changes

Changes do not alter the basic nature of a substance.

Chemical Changes

Changes that alter the chemical composition of a substance.

Energy

The ability to do work; has no mass or occupies space; includes kinetic and potential forms.

Kinetic Energy

Energy in action; energy doing work.

Potential Energy

Stored or inactive energy; energy available to do work.

Chemical Energy

Energy stored in chemical bonds of substances.

Electrical Energy

Energy resulting from movement of charged particles.

Mechanical Energy

Energy directly involved in moving matter.

Radiant Energy

Energy that travels in waves (electromagnetic spectrum).

ATP (Adenosine Triphosphate)

Cellular energy currency; traps chemical energy of food in its bonds.

Four Major Elements

Oxygen (O), Carbon (C), Hydrogen (H), Nitrogen (N) — make up about 96% of body mass.

Oxygen (O)

Major element; ~65% of body mass; essential for energy production as a gas.

Carbon (C)

Major element; primary through organic molecules (carbs, lipids, proteins, nucleic acids).

Hydrogen (H)

Major element; component of all organic molecules; influences pH.

Nitrogen (N)

Major element; component of proteins and nucleic acids.

Trace Elements

Elements required in very small amounts (e.g., Cr, Co, Cu, F, Mn, Mo, Se, Si, Sn, V, Zn).

Atom

Building block of elements; differs between elements; has a chemical symbol.

Atomic Symbol

Shorthand notation for an element."

Proton

Positively charged subatomic particle in the nucleus; mass ~1 amu.

Neutron

Electrically neutral subatomic particle in the nucleus; mass ~1 amu.

Electron

Negatively charged subatomic particle orbiting the nucleus; mass ~0 amu (negligible).

Atomic Number

Number of protons in an atom; unique to each element; indirectly indicates electrons.

Atomic Mass Number

Sum of protons and neutrons in the nucleus.

Atomic Weight

Approximately the mass number of the element’s most abundant isotope.

Isotope

Atoms with same protons/electrons but different number of neutrons; same atomic number, different mass.

Ion

Atom that has gained or lost electrons, resulting in a net charge.

Cation

Positively charged ion; loss of electrons.

Anion

Negatively charged ion; gain of electrons.

Ionic Bond

Bond formed by the transfer of electrons; attraction between opposite charges (e.g., NaCl).

Covalent Bond

Bond formed when atoms share electrons; can be single or multiple bonds.

Nonpolar Covalent

Electrons shared equally; molecule is electrically neutral (e.g., CO2).

Polar Covalent

Electrons not shared equally; molecule has partial charges (e.g., H2O).

Hydrogen Bond

Extremely weak bond between a hydrogen atom and a negative portion of a polar molecule; important in water and proteins.

Electron Shell

Energy levels around the nucleus where electrons reside.

Valence Shell

Outermost electron shell; bonding involves outermost electrons.

Octet Rule

Atoms are most stable when the valence shell has 8 electrons (shell 1 holds 2).

Synthesis

Atoms or molecules combine to form larger, more complex molecules; energy absorbed.

Decomposition

A molecule is broken into smaller molecules; energy released.

Exchange Reaction

Bonds are formed and broken; parts switch between molecules.

Reversibility

Most reactions are reversible; indicated by a double arrow.

Temperature Effect on Rate

Increasing temperature raises kinetic energy, increasing collision rate and reaction speed.

Concentration Effect on Rate

Higher concentration increases collision frequency and reaction rate.

Particle Size Effect on Rate

Smaller particles have greater surface area and react more quickly.

Catalyst

Substance that speeds up a reaction by lowering activation energy.

Inorganic Compounds

Compounds that lack carbon or are simple; include water, salts, acids, and bases.

Organic Compounds

Compounds that contain carbon; typically large covalent molecules (carbohydrates, lipids, proteins, nucleic acids).

Water Properties

Major inorganic compound; high heat capacity, polarity/solvent properties, chemical reactivity, cushioning.

Universal Solvent

Water; dissolves many solutes to form solutions.

Hydrolysis

Water is added to break bonds in polymers.

Dehydration Synthesis

Monomers join by removing water to form a polymer.

Monosaccharide

Simple sugar; 3–7 carbon atoms (e.g., glucose, fructose, galactose, ribose, deoxyribose).

Disaccharide

Two simple sugars joined by dehydration synthesis; e.g., sucrose, lactose, maltose.

Polysaccharide

Long, branched chains of simple sugars; storage molecules (e.g., starch, glycogen).

Lipids

Contain carbon, hydrogen, and oxygen; mostly insoluble in water; major types: triglycerides, phospholipids, steroids.

Triglycerides

Neutral fats; glycerol + three fatty acids; energy storage and insulation.

Saturated Fatty Acids

Single covalent bonds between carbons; straight chains; solid at room temperature.

Unsaturated Fatty Acids

double bonds; kinked chains; liquids at room temperature.

Trans Fats

Hydrogenated fats; higher risk of heart disease.

Phospholipids

Two fatty acid chains; hydrophobic tails and hydrophilic head; form cell membranes.

Steroids

Four interlocking carbon rings; include cholesterol, bile salts, vitamin D, hormones.

Cholesterol

Steroid; basis for steroid hormones; obtained from diet and synthesized by liver.

Proteins

Large biomolecules that provide structure, enzymes, hormones, antibodies; built from amino acids.

Amino Acids

Building blocks of proteins; contain an amine group, carboxyl group, and variable R-group.

Protein Primary Structure

Linear sequence of amino acids in a polypeptide.

Protein Secondary Structure

Alpha helix or beta-pleated sheet; stabilized by hydrogen bonds.

Protein Tertiary Structure

Three-dimensional folding of a single polypeptide.

Protein Quaternary Structure

Arrangement of two or more polypeptide chains in a protein.

Fibrous Proteins

Structural proteins with extended shapes (e.g., collagen, keratin); provide support.

Globular Proteins

Functional proteins (antibodies, hormones, enzymes); typically spherical.

Enzymes

Biological catalysts that speed up chemical reactions by lowering activation energy; many end with -ase.

Active Site

Region of an enzyme where substrates bind to catalyze a reaction.

DNA

Deoxyribonucleic acid; genetic material; double-stranded helix with bases A, T, C, G.

RNA

Ribonucleic acid; single-stranded; bases A, U, C, G; roles in protein synthesis.

Nucleotides

Building blocks of nucleic acids; consist of a nitrogenous base, a sugar, and a phosphate group.