Introductory Biology: Macromolecules, Chemistry of Life, and Cell Structure

Vocabulary practice flashcards covering chemical bonding, characteristics of life, water properties, macromolecule classes, and cell membrane structures from BIOL 1124 lectures.

Atom

The smallest chemical unit of a type of pure substance (element).

Molecule

A chemical structure consisting of two or more atoms held together by chemical bonds.

Cell

The fundamental unit of life.

Homeostasis

The process of maintaining a state of internal biological equilibrium, such as temperature, water, pH, and sugar levels.

Covalent Bond

An intra-molecular chemical bond formed when atoms share electrons.

Nonpolar Covalent Bond

A covalent bond in which bonding electrons are shared equally between two atoms, resulting in no charges on the atoms.

Polar Covalent Bond

A covalent bond in which bonding electrons are shared unequally between two atoms, resulting in partial positive ($\delta+$) and partial negative ($\delta-$) charges.

Ionic Bond

A chemical bond formed by the complete transfer of one or more valence electrons, creating ions of opposite charges that attract each other.

Hydrogen Bond

A weak inter-molecular attraction formed between the partial charges of polar molecules.

Oxidation

The loss of an electron by an atom or molecule during a chemical reaction.

Reduction

The gain of an electron by an atom or molecule during a chemical reaction.

Types of Chemical Bonds Diagram

A diagram comparing a nonpolar covalent bond (equal sharing), a polar covalent bond (unequal sharing), and an ionic bond (complete electron transfer).

Redox Reaction Diagram

An illustration showing oxidation as the loss of an electron and reduction as the gain of an electron.

Hydrophilic

Water-loving; descriptive of polar molecules and charged ions that dissolve easily in water.

Hydrophobic

Water-fearing; descriptive of nonpolar, uncharged molecules (such as fats and waxes) that do not dissolve in water.

Monomer

A small, single molecular subunit that can bind to other subunits to form a polymer.

Polymer

A large molecule consisting of linked, repeating monomer subunits.

Dehydration Synthesis

A condensation reaction that joins monomers together by releasing a molecule of water ($H_2O$).

Hydrolysis Reaction

A chemical reaction that cleaves polymers into monomers by adding a molecule of water ($H_2O$).

Monosaccharide

The monomer of carbohydrates, containing a carbon backbone (usually a ring), which functions as the most common metabolic fuel for life.

Polysaccharide

A carbohydrate polymer formed by connecting multiple monosaccharides together end-to-end.

Polypeptide

A linear chain of amino acids linked together by peptide bonds.

Protein

A functional macromolecule consisting of one or more polypeptides folded and shaped in a specific 3D structure.

Amino Acid

The monomer of proteins, consisting of a core structure and a unique R group that determines its chemical behavior.

Protein Structure Levels

The four structural levels of a protein: primary (amino acid sequence), secondary, tertiary, and quaternary structure.

Hydrophobic Exclusion

The process by which a polypeptide folds in water to minimize exposure of nonpolar R-groups, hiding them inside the protein structure.

Denaturation

The disruption of weak hydrogen bonds in a protein caused by factors like heat, protons ($H^+$), or hydroxides ($OH^-$), altering its structure and eliminating its function.

Lipid

A diverse class of organic molecules (including fats, oils, waxes, and steroids) that are at least partially hydrophobic and composed of sub-units such as heads and fatty acid tails.

Nucleic Acid

A class of organic macromolecules (such as DNA and RNA) made of nucleotide monomers that store genetic information.

Phospholipid Bilayer

A membrane structure composed of two layers of phospholipids, with polar hydrophilic heads contacting water and nonpolar hydrophobic tails oriented inward.

Amphipathic Molecule

A molecule (such as a phospholipid) containing both hydrophilic (polar) and hydrophobic (nonpolar) regions.

Transmembrane Protein

An integral membrane protein that spans the lipid bilayer, featuring hydrophobic regions contacting fatty acid tails and hydrophilic regions contacting aqueous surroundings.