Lecture 2: Chemistry of Life Flashcards

Vocabulary flashcards summarizing fundamental concepts of human body chemistry, atomic structures, chemical bonds, reactions, inorganic substances, and major organic macromolecules from Chapter 2.

Matter

Anything that takes up space and has mass.

Mass

The amount of matter present.

Weight

The heaviness of matter due to gravitational pull on mass.

Chemistry

The study of the composition, properties, and interactions of matter.

Biochemistry

Biological chemistry studying physiological processes and disease.

Elements

Simplest types of matter with certain chemical properties, totaling 92 naturally occurring forms.

Bulk Elements

Elements required in the body in large amounts, including $C$, $O$, $H$, $N$, $S$, and $P$.

Trace Elements

Elements required in the body in small amounts, such as $Fe$ and $I$.

Ultratrace Elements

Elements required in the body in very minute amounts, such as $As$.

Compound

A combination of two or more atoms of different elements chemically combined.

Atoms

The smallest particles of an element that retain the chemical properties of that element.

Atomic Number

The number of protons in the nucleus of an atom of a specific element.

Mass Number

The total number of protons plus neutrons in an atom.

Isotopes

Atoms with the same atomic number but different mass numbers due to differing numbers of neutrons.

Atomic Weight

The average of all mass numbers of the isotopes of an element.

Molecule

Two or more atoms chemically combined.

Ion

An electrically charged atom formed when an atom gains or loses electrons to become stable.

Cation

A positively charged ion formed when an atom loses electrons.

Anion

A negatively charged ion formed when an atom gains electrons.

Ionic Bond

A strong chemical bond formed by the attraction between ions of opposite charges.

Covalent Bond

A strong chemical bond formed between atoms that share electrons.

Nonpolar Covalent Bond

A covalent bond in which electrons are shared equally between atoms with the same electronegativity.

Polar Covalent Bond

A covalent bond in which electrons are shared unequally due to differences in electronegativity.

Hydrogen Bond

A relatively weak attraction between the slightly positive end of one polar molecule and the slightly negative end of another polar molecule.

Reactants

The starting materials in a chemical reaction.

Products

The substances formed at the end of a chemical reaction.

Synthesis Reaction

A chemical reaction in which a more complex structure is formed from simpler starting components.

Decomposition Reaction

A chemical reaction in which chemical bonds are broken to form simpler structures.

Exchange Reaction

A chemical reaction in which bonds are broken and new bonds are formed to trade components.

Reversible Reaction

A chemical reaction in which the products can change back into reactants.

Electrolytes

Substances that release ions in water and can conduct an electric current.

Acids

Electrolytes that dissociate in water to release hydrogen ions ($H^+$).

Bases

Substances that release ions capable of combining with hydrogen ions ($H^+$).

Salts

Electrolytes formed by the reaction between an acid and a base.

pH Scale

A shorthand scale ranging from 0 to 14 measuring the concentration of $H^+$ ions in body fluids.

Organic Molecules

Molecules containing $C$ and $H$ that dissolve in water or organic liquids and do not release ions if water-soluble.

Inorganic Molecules

Molecules that generally lack $C$ and $H$, dissolve in water, dissociate into ions, and act as electrolytes.

Monosaccharides

Single sugar units such as glucose and fructose.

Disaccharides

Double sugar molecules such as sucrose and lactose.

Polysaccharides

Complex carbohydrates composed of many joined sugar units, such as starch, glycogen, and cellulose.

Triglycerides

The most abundant lipids in the body used for cellular energy, consisting of 1 molecule of glycerol and 3 fatty acids.

Saturated Fatty Acids

Fatty acid chains containing only single $C-C$ bonds, typically solid at room temperature and derived from animals.

Unsaturated Fatty Acids

Fatty acid chains containing at least one $C-C$ double bond, typically liquid at room temperature and derived from plants.

Phospholipids

Lipids consisting of 1 glycerol, 2 fatty acids, and 1 phosphate group, forming the main component of cell membranes.

Steroids

Lipids composed of 4 connected carbon rings, used to synthesize adrenal and sex hormones, with cholesterol as the primary example.

Proteins

Organic molecules composed of amino acids connected by peptide bonds, functioning as structures, enzymes, antibodies, receptors, and hormones.

Amino Acids

The building blocks of proteins, containing an amino group, a carboxyl group, and a unique R group.

Peptide Bonds

Chemical bonds formed between the amino group of one amino acid and the carboxyl group of an adjacent amino acid.

Denaturation

A dramatic change in the secondary and tertiary structure of a protein caused by heat, radiation, pH changes, or chemicals.

Nucleic Acids

Organic molecules composed of nucleotides that carry the genetic code (DNA) or assist in protein synthesis (RNA).

Nucleotides

The building block units of nucleic acids, each composed of a sugar, a phosphate group, and an organic base.