Biomolecules: Primary and Secondary Metabolites, Biomacromolecules, and Proteins

Vocabulary practice cards focusing on primary and secondary metabolites, the distinction between micromolecules and biomacromolecules, lipid fractionation, and basic protein concepts.

Primary metabolites

Biomolecules found in animal tissues that have identifiable functions and play known roles in normal physiological processes.

Secondary metabolites

Compounds produced by plant, fungal, and microbial cells—such as alkaloids, flavonoids, rubber, and antibiotics—whose specific physiological roles in host organisms are not yet fully understood, though many have ecological importance or human welfare uses.

Pigments (Secondary Metabolites)

A category of secondary metabolites that includes carotenoids and anthocyanins.

Alkaloids

A class of secondary metabolites exemplified by morphine and codeine.

Terpenoides

A category of secondary metabolites exemplified by monoterpenes and diterpenes.

Essential oils

A category of secondary metabolites that includes lemon grass oil.

Toxins (Secondary Metabolites)

A class of secondary metabolites exemplified by abrin and ricin.

Lectins

A category of secondary metabolites exemplified by Concanavalin A.

Drugs (Secondary Metabolites)

A class of secondary metabolites exemplified by vinblastin and curcumin.

Polymeric substances (Secondary Metabolites)

A category of secondary metabolites that includes rubber, gums, and cellulose.

Acid soluble pool

The fraction obtained during tissue analysis roughly representing cytoplasmic composition, consisting of micromolecules with molecular weights ranging from $18$ to around $800\text{ daltons (Da)}$.

Acid insoluble fraction

The fraction obtained during tissue analysis representing cytoplasm and organelles, containing macromolecules (proteins, nucleic acids, and polysaccharides) as well as lipids.

Micromolecules

Chemical compounds found in living organisms that have molecular weights of less than $1{,}000\text{ daltons (Da)}$ and are found in the acid soluble pool.

Biomacromolecules

Molecules found in the acid insoluble fraction with molecular weights typically in the range of ten thousand daltons ($10{,}000\text{ Da}$) and above, which are polymeric substances.

Lipids (Analytical Classification)

Small molecular weight compounds not exceeding $800\text{ Da}$ that are non-polymeric, but are recovered in the acid insoluble fraction because their membrane structures break into water-insoluble vesicles upon cell disruption.

Proteins

Heteropolymers composed of linear chains of amino acids linked together by peptide bonds.

Heteropolymer

A polymer made up of different types of monomeric units, such as a protein constructed from $20$ different types of amino acids.

Homopolymer

A polymer that consists of only a single type of monomer repeated $n$ number of times.

Essential amino acids

Amino acids that cannot be synthesized by the human body and must be supplied through dietary intake.

Non-essential amino acids

Amino acids that the body is capable of synthesizing on its own.