Basic Chemistry and Biomolecules

Comprehensive vocabulary flashcards covering basic chemistry, types of chemical bonds, reactions, solutions, and major classes of biological macromolecules based on textbook notes.

Matter

Anything that occupies space and has mass.

Mass

The amount of matter in an object.

Weight

The gravitational force acting on an object of a given mass.

Element

The simplest type of matter, having unique chemical properties.

Atom

The smallest particle of an element that retains the chemical characteristics of that element.

Neutron

A subatomic particle located in the nucleus of an atom that has no electrical charge.

Proton

A subatomic particle located in the nucleus of an atom that carries one positive electrical charge.

Electron

A subatomic particle located in an electron cloud orbiting the nucleus that carries one negative electrical charge.

Nucleus

The dense center of an atom containing protons and neutrons, accounting for 99.97\text{\textpercent} of the atom's mass.

Atomic number

The number equal to the number of protons (and equal to the number of electrons) in each atom of an element.

Mass number

The total number of protons plus the number of neutrons in each atom of an element.

Isotopes

Two or more forms of the same element that have the same number of protons and electrons but a different number of neutrons.

Atomic mass

The average mass of an element's naturally occurring isotopes, taking into account the relative abundance of each isotope.

Mole

A quantity of a substance containing Avogadro's number ($6.022 \times 10^{23}$) of entities such as atoms, ions, or molecules.

Molar mass

The mass of one mole of a substance expressed in grams.

Valence shell

The outermost electron shell of an atom, which determines the atom's chemical nature and reactivity.

Octet rule

The tendency of atoms to combine with other atoms until each has eight electrons in its valence shell (or two electrons for hydrogen).

Electronegativity

The ability of an atom's nucleus to attract electrons.

Ion

A charged particle formed when an atom gains or loses electrons.

Cation

A positively charged ion formed when an atom loses one or more electrons.

Anion

A negatively charged ion formed when an atom gains one or more electrons.

Ionic bond

A chemical bond formed when electrons are transferred between atoms, creating oppositely charged ions that attract each other.

Covalent bond

A chemical bond formed when two or more atoms share one or more pairs of electrons.

Nonpolar covalent bond

A covalent bond in which electrons are shared equally between atoms because they have the same attraction to each nucleus.

Polar covalent bond

A covalent bond formed between atoms with different electronegativities, resulting in an unequal sharing of electrons and asymmetric electrical charges.

Molecule

A structure composed of two or more atoms chemically combined to form an independent unit.

Compound

A substance resulting from the chemical combination of two or more different types of atoms.

Intermolecular forces

Weak electrostatic attractions that exist between oppositely charged parts of molecules or between ions and molecules without electron exchange.

Hydrogen bond

An intermolecular attraction formed when a positively charged hydrogen atom in a polar molecule is attracted to a negatively charged oxygen, nitrogen, or fluorine atom in another molecule.

Solubility

The ability of one substance to dissolve in another.

Dissociation

The separation of cations and anions from one another when an ionic compound dissolves in water.

Electrolytes

Cations and anions that dissociate in water and possess the capacity to conduct an electric current.

Nonelectrolytes

Molecules that dissolve in water without dissociating into ions, forming solutions that do not conduct electricity.

Synthesis reaction

A chemical reaction in which two or more reactants chemically combine to form a new and larger product.

Anabolism

The collective term for synthesis reactions occurring in the body that build complex molecules.

Decomposition reaction

A chemical reaction in which a larger reactant is chemically broken down into two or more smaller products.

Catabolism

The collective term for decomposition reactions occurring in the body.

Metabolism

The sum of all anabolic and catabolic reactions taking place in the body.

Reversible reaction

A chemical reaction that can proceed in either direction so that products can be converted back into the original reactants.

Chemical equilibrium

The state in a reversible reaction when the rate of product formation equals the rate of the reverse reaction, maintaining constant amounts of reactants and products.

Oxidation

The loss of one or more electrons by an atom or molecule during a chemical reaction.

Reduction

The gain of one or more electrons by an atom or molecule during a chemical reaction.

Potential energy

Stored energy that has the capacity to do work but is not currently doing so.

Kinetic energy

The form of energy that is actively doing work and moving matter.

Activation energy

The minimum amount of energy that reactants must possess to initiate a chemical reaction.

Catalyst

A substance that increases the rate of a chemical reaction without being permanently changed or consumed.

Enzymes

Protein catalysts that accelerate chemical reactions in living systems by lowering activation energy.

Hydrophilic

Molecules that are attracted to water due to their polar or charged nature ('water loving').

Hydrophobic

Molecules that lack attraction to water due to their nonpolar nature ('water fearing').

Cohesion

The attractive force between water molecules holding them together via hydrogen bonding.

Adhesion

The attractive force between water molecules and other non-water molecules via hydrogen bonding.

Solute

The substance that is dissolved in a solvent to form a solution.

Solvent

The liquid or medium in which a solute is dissolved to form a solution.

Suspension

A mixture containing materials that will separate from one another unless continually and physically mixed.

Colloid

A mixture containing evenly dispersed, small particles that do not settle out over time.

Acid

A proton donor; a molecule or compound that releases hydrogen ions ($\text{H}^+$) in solution.

Base

A proton acceptor; a substance that binds to or accepts hydrogen ions ($\text{H}^+$) in solution.

pH scale

A scale ranging from $0$ to $14$ that indicates the hydrogen ion ($\text{H}^+$) concentration of a solution.

Acidosis

A clinical condition occurring when blood pH falls below $7.35$, causing nervous system depression.

Alkalosis

A clinical condition occurring when blood pH rises above $7.45$, causing nervous system overexcitability.

Buffer

A chemical or mixture of chemicals that resists dramatic changes in pH when acids or bases are added.

Monosaccharides

Simple sugar molecules that serve as the fundamental building blocks of carbohydrates.

Isomers

Molecules that share the same molecular formula but differ in their three-dimensional structural arrangements.

Disaccharides

Carbohydrates composed of two monosaccharides joined together through a dehydration reaction.

Polysaccharides

Complex carbohydrates composed of long chains of monosaccharides linked together.

Lipids

Organic molecules composed mainly of carbon, hydrogen, and oxygen that are characteristically insoluble in water.

Triglycerides

The primary form of fat in the human body (95\text{\textpercent}), consisting of one glycerol molecule bound to three fatty acids.

Phospholipids

Structural lipids consisting of a glycerol, two fatty acids, and a phosphate group, possessing a polar hydrophilic head and nonpolar hydrophobic tails.

Eicosanoids

A group of regulatory lipid molecules derived from fatty acids, including prostaglandins, thromboxanes, and leukotrienes.

Steroids

Lipids composed of four interconnected carbon ring structures, such as cholesterol and steroid hormones.

Peptide bonds

Covalent bonds linking amino acid monomers together during protein synthesis.

Denaturation

The structural alteration of a protein caused by breaking hydrogen bonds, resulting in a loss of biological function.

Nucleotides

The building blocks of nucleic acids, consisting of a monosaccharide sugar, a nitrogenous base, and a phosphate group.

Gene

A sequence of DNA bases that provides instructions for synthesizing specific proteins or RNA molecules.

Adenosine Triphosphate (ATP)

The principal energy currency of cells, consisting of adenosine, ribose, and three phosphate groups.