Chapter 2: Chemistry of Life Vocabulary

Vocabulary flashcards covering fundamental chemistry terms, subatomic structures, chemical bonding, reactions, solutions, and biological macromolecules from Chapter 2.

Matter

Anything that has mass and occupies space.

Weight

The pull of gravity on mass.

Solid

A state of matter characterized by a definite shape and a definite volume.

Liquid

A state of matter characterized by a changeable shape and a definite volume.

Gas

A state of matter characterized by a changeable shape and a changeable volume.

Protons

Subatomic particles with a positive charge ($+\text{ charge}$) located inside the atomic nucleus.

Neutrons

Subatomic particles with no charge located inside the atomic nucleus.

Electrons

Subatomic particles with a negative charge ($-\text{ charge}$) that orbit the nucleus in an electron cloud.

Atomic number

The number of protons contained in the nucleus of an element.

Mass number

The total number of protons and neutrons in the nucleus of an atom.

Isotopes

Nuclides with the same atomic number but different mass numbers.

Carbon-14

An isotope of carbon containing $6$ protons and $8$ neutrons, commonly used for radioactive carbon dating.

Molecular compounds

Molecules containing more than one element.

Solutions

Homogeneous mixtures formed when gases, liquids, or solids are dissolved in water.

Solvent

The substance present in the greatest amount in a solution, usually a liquid such as water.

Solute

The substance present in smaller amounts in a solution.

Colloids (Emulsions)

Heterogeneous mixtures in which large solute particles do not settle out and can undergo sol-gel transformations.

Suspensions

Heterogeneous mixtures containing large, visible solutes that settle out of the mixture.

Ionic Bonds

Chemical bonds formed when electrons are transferred from one atom to another, resulting in oppositely charged ions that attract each other.

Covalent Bonds

Chemical bonds formed when atoms share electron pairs.

Hydrogen Bond

A weak attraction formed when the slightly positive end (\text{\textdelta}+) of one polar molecule aligns with the slightly negative end (\text{\textdelta}-) of another polar molecule.

Synthesis reactions

Chemical reactions in which smaller particles are bonded together to form larger, more complex molecules.

Decomposition reactions

Chemical reactions where bonds are broken in larger molecules, resulting in smaller, less complex molecules.

Exchange reactions

Reactions in which chemical bonds are both made and broken; also known as displacement reactions.

Exergonic reactions

Chemical reactions that yield a net release of energy.

Endergonic reactions

Chemical reactions that result in a net absorption of energy.

Catalysts

Substances that increase the rate of a chemical reaction without being chemically changed or becoming part of the product.

Inorganic compounds

Compounds that do not contain carbon, including water, salts, and many acids and bases.

Organic compounds

Carbon-containing molecules that are usually large and covalently bonded, including carbohydrates, lipids, proteins, and nucleic acids.

Acids

Electrolytes that act as proton donors by ionizing and dissociating in water to release $H^+$.

Bases

Electrolytes that act as proton acceptors by taking up $H^+$ from a solution.

Buffers

Chemical systems that resist abrupt and large swings in $pH$ by releasing hydrogen ions when $pH$ rises or binding hydrogen ions when $pH$ falls.

Monosaccharides

Single-sugar molecules that serve as the monomers of carbohydrates, such as hexose (glucose) and pentose (ribose, deoxyribose) sugars.

Disaccharides

Double sugars, such as sucrose, maltose, and lactose, that are too large to pass directly through cell membranes.

Polysaccharides

Insoluble polymers of monosaccharides, such as plant starch and animal glycogen.

Triglycerides

Lipids composed of fatty acids and glycerol that function in energy storage, insulation, and organ protection.

Phospholipids

Modified triglycerides composed of glycerol, two fatty acids, and a phosphorus-containing group that form cell membrane structures.

Steroids

Lipids composed of a flat four-ring structure, including cholesterol, vitamin D, steroid hormones, and bile salts.

Amino acids

The $20$ distinct monomer types that unite via peptide bonds to form proteins; each contains an amine group, an acid group, and a unique R group.

Fibrous Proteins

Strand-like, water-insoluble, and stable structural proteins that provide mechanical support and tensile strength, such as collagen and keratin.

Globular Proteins

Compact, spherical, water-soluble functional proteins with specific active sites that are sensitive to environmental changes.

Protein Denaturation

The process in which globular proteins unfold and lose their functional 3-D shape and active sites due to factors like decreased $pH$ or elevated temperature.

Enzymes

Globular proteins that function as biological catalysts to lower activation energy and accelerate specific chemical reactions.

Deoxyribonucleic Acid (DNA)

A double-stranded nucleic acid located inside the cell nucleus that uses adenine, guanine, cytosine, and thymine to store instructions for protein synthesis.

Ribonucleic Acid (RNA)

A single-stranded nucleic acid located outside the cell nucleus that contains ribose sugar and utilizes uracil in place of thymine.

Adenosine Triphosphate (ATP)

An adenine-containing RNA nucleotide with two additional phosphate groups that serves as the primary chemical energy currency of the cell.

Phosphorylation

The enzymatic transfer of ATP's terminal phosphate group to another molecule, energizing it to perform cellular work.