An Intro to Chemistry - Exam 1 Flashcards

Vocabulary flashcards generated from the Chapter 2 study guide answer key covering chemical definitions, bond types, properties of water, and biological macromolecules.

Element

A pure substance made of only one type of atom.

Atom

The smallest unit of an element that retains the element's properties.

Molecule

Two or more atoms held together by covalent bonds.

Isotope

Atoms of the same element with the same number of protons but different numbers of neutrons.

Macromolecule

A very large biological molecule, such as a carbohydrate, lipid, protein, or nucleic acid.

Polymer

A large molecule made from repeating smaller units called monomers.

Hydrophilic

Attracted to/interacts readily with water; usually polar or charged.

Hydrophobic

Repelled by or does not mix well with water; usually nonpolar.

Acid

A substance that increases $H^+$ concentration in water; pH below $7$.

Base

A substance that decreases $H^+$ concentration or increases $OH^-$ concentration; pH above $7$.

CHNOPS

Acronym for the six most common biological elements: Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfur.

Covalent bond

A bond where atoms share electrons; may be polar (unequal sharing) or nonpolar (more equal sharing).

Ionic bond

A bond where electrons are transferred from one atom to another, producing positively and negatively charged ions that attract each other.

Hydrogen bond

A relatively weak attraction between a partially positive hydrogen and an electronegative atom, commonly oxygen or nitrogen.

Van der Waals interactions

Very weak attractions caused by temporary or induced partial charges.

Solubility

The ability of a substance (solute) to dissolve in another substance (solvent).

pH scale

A scale measuring the concentration of hydrogen ions ($H^+$) in a solution, where each whole-number change represents a $10$-fold change in $H^+$ concentration.

Cohesion

A property of water where water sticks to water.

Adhesion

A property of water where water sticks to other polar surfaces.

High specific heat

A property of water where water resists rapid temperature changes.

High heat of vaporization

A property of water where evaporation requires substantial energy, producing cooling.

Carbohydrates

Molecules containing mainly C, H, and O that include sugars and starches; used for quick energy, energy storage, and structural support, with common building blocks being monosaccharides such as glucose.

Lipids

Molecules including fats, oils, phospholipids, and steroids that are mostly hydrophobic; important for long-term energy storage, insulation, membranes, and signaling.

Nucleic acids

DNA and RNA; made of nucleotides; store, transmit, and help express genetic information.

Proteins

Polymers of amino acids that perform many functions including enzymes, structure, transport, movement, defense, and signaling.