Macromolecules and Biochemical Reactions Vocabulary Flashcards

Monomer

A small molecule that can combine covalently with other similar or identical molecules to form a polymer.

Polymer

A large molecule made by covalent bonding of smaller repeating subunits called monomers.

Condensation Reaction

A chemical reaction (also called a dehydration reaction) that links monomers together into polymers by removing water molecules.

Hydrolysis Reaction

A chemical reaction that breaks a polymer apart into individual monomers through the addition of water.

Lipids

Nonpolar, hydrophobic biological molecules (such as fats, waxes, and sterols) that are insoluble in water due to many nonpolar covalent bonds and are held together by weak van der Waals forces when aggregated.

Trlycerides

Simple fats and oils composed of a single glycerol molecule attached to three fatty acid chains via ester bonds.

Saturated Fatty Acid

A fatty acid in which all carbon-carbon bonds in the hydrocarbon chain are single bonds, allowing straight molecules to pack tightly together, resulting in a higher melting temperature ($T_m$) and a solid state at room temperature.

Unsaturated Fatty Acid

A fatty acid containing one or more carbon-carbon double bonds in its hydrocarbon chain, causing kinks that prevent orderly packing and resulting in a lower melting temperature ($T_m$) and liquid state at room temperature.

Phospholipid

An amphipathic lipid molecule consisting of a glycerol backbone bound to two fatty acid tails and a strongly hydrophilic, charged phosphate-containing head group.

Phospholipid Bilayer

A two-layered sheet formed by phospholipids in aqueous environments, where nonpolar hydrophobic tails pack inside away from water and hydrophilic heads face outward to interact with water.

Carotenoids

Light-absorbing lipid pigments that function to absorb sunlight energy in plants and other organisms.

Carbohydrates

Biological molecules formed by linking sugar monomers (monosaccharides) together, characterized by the general formula $C_m(H_2O)_n$.

Monosaccharide

A simple sugar monomer containing 12 or fewer carbon atoms that can exist in straight-chain or ring forms.

Structural Isomers

Molecules that share the same molecular formula but have a different bonding arrangement among their constituent atoms.

Stereoisomers

Molecules that share the same molecular formula and atom-to-atom bonding arrangement, but differ in the three-dimensional spatial orientation of their functional groups.

Glycosidic Linkage

A covalent bond that joins monosaccharides together into disaccharides, oligosaccharides, or polysaccharides via a condensation reaction.

Oligosaccharide

A carbohydrate polymer formed from 3 to 10 monosaccharide units linked together by glycosidic bonds.

Polysaccharide

A large carbohydrate polymer composed of many monosaccharides joined by glycosidic linkages, which may be linear or branched.

Ribose

A five-carbon pentose sugar ($C_5H_{10}O_5$) containing a hydroxyl group ($-OH$) attached to its second carbon ($C_2$), forming part of the sugar backbone of RNA, ATP, and NAD.

Deoxyribose

A five-carbon pentose sugar ($C_5H_{10}O_4$) containing a hydrogen atom ($-H$) instead of a hydroxyl group on its second carbon ($C_2$), forming the sugar backbone of DNA.

Nucleic Acids

Polymers (such as DNA and RNA) specialized for storing, transmitting, and expressing genetic information in living organisms.

Nucleotide

The monomer subunit of nucleic acids, consisting of a nitrogenous base, a pentose sugar (ribose or deoxyribose), and one to three phosphate groups.

Pyrimidines

Single-ring nitrogenous bases found in nucleic acids, including Cytosine (C), Thymine (T), and Uracil (U).

Purines

Double-ring nitrogenous bases found in nucleic acids, including Adenine (A) and Guanine (G).

Phosphodiester Linkage

A covalent bond formed during a condensation reaction that links nucleotides together by connecting the 5'-phosphate group of a new nucleotide to the 3'-OH group of the existing nucleic acid chain.

Complementary Base Pairing

Specific hydrogen bonding between purine and pyrimidine bases in nucleic acids (Adenine pairing with Thymine or Uracil, and Guanine pairing with Cytosine).

Amino Acid

The monomer building block of proteins