Biochemistry and Chemical Foundations of Life

A complete set of vocabulary flashcards covering chemical reactions, water, acids and bases, carbohydrates, lipids, proteins, enzymes, and nucleic acids.

Synthesis Reaction

A chemical reaction where smaller atoms combine to form larger ones ($A + B \rightarrow AB$), which is used in anabolic processes.

Decomposition Reaction

A chemical reaction that breaks down molecules into smaller ones ($AB \rightarrow A + B$).

Exchange Reaction

A chemical reaction involving swapping partners ($AB + CD \rightarrow AC + BD$) that involves both synthesis and decomposition, also called a displacement reaction.

Water

The most abundant inorganic compound, making up $60\text{-}80\%$ of the volume of living cells, characterized by high heat capacity, high heat of vaporization, polar reactivity, cushioning, cohesive behavior, moderate temperature, expansion upon freezing, and versatility as a solvent.

Acid

An electrolyte that acts as a proton donor by releasing hydrogen ions ($H^+$), causing $H^+$ concentration to increase and pH to decrease; important examples include $HCl$, $HAc$, and carbonic acid.

Base

An electrolyte that acts as a proton acceptor by releasing hydroxyl ions ($OH^-$) or accepting $H^+$, causing $H^+$ concentration to decrease and pH to increase; important examples include bicarbonate ion and ammonia.

Buffer

A chemical substance that resists sudden changes in pH by accepting or releasing $H^+$ to keep internal conditions stable and maintain homeostasis.

Dehydration Reaction

A reaction that joins two monomers together to form a larger molecule by removing a $H_2O$ molecule.

Glycosidic Bond

The specific bond that connects sugar molecules together.

Hydrolysis Reaction

A reaction that breaks larger molecules into smaller units by adding water ($H_2O$).

Monosaccharide

A single ring sugar molecule containing $3\text{-}7$ carbons that provides energy and building blocks for larger carbohydrates; examples include glucose, fructose, galactose, ribose, and deoxyribose.

Disaccharide

A carbohydrate formed by linking two monosaccharides via dehydration synthesis, serving as transportable or dietary forms of carbohydrates such as sucrose, maltose, and lactose.

Polysaccharide

A long chain of monosaccharides primarily used for energy storage, such as glycogen, cellulose, and starch.

Triglyceride

A lipid composed of 1 glycerol backbone and 3 fatty acid chains that stores energy, protects, and insulates organs; examples include fats, oils, and butter.

Phospholipid

An amphipathic lipid consisting of 1 polar, hydrophilic head and 2 nonpolar, hydrophobic fatty acid tails, serving as a major component of cell membranes.

Steroid

A lipid structured with 4 interlocked carbon rings; includes cholesterol, which is part of cell membranes and is used to make steroid hormones, vitamin D, and bile salts.

Peptide Bond

The chemical bond that links amino acid monomers together to form polypeptide chains that fold into proteins.

Protein

A biological macromolecule made of amino acid monomers that serves cellular functions including structure (collagen in bones), enzymes, transport (hemoglobin), membrane transport, movement, cell signaling, and defense (antibodies).

Denaturation

The process in which a protein loses its 3D shape and normal function, caused by high temperature, pH changes, salts, or heavy metals.

Enzyme

A protein catalyst with a specific 3D shape that speeds up biochemical reactions by lowering activation energy.

Active Site

The specific region on an enzyme where the substrate binds to undergo a reaction.

Nucleic Acid

A biological macromolecule composed of nucleotide monomers (such as DNA and RNA) that functions to store, transmit, and use genetic information to provide instructions for making proteins.

DNA (Deoxyribonucleic Acid)

A long-term storage nucleic acid containing deoxyribose sugar and bases A, T, C, and G that stores genetic information and helps make RNA and proteins.

RNA (Ribonucleic Acid)

A short-term use nucleic acid containing ribose sugar and bases A, U, C, and G that carries out DNA instructions to help make proteins.