Is ribosome a simile or metaphor?

A ribosome is neither a simile nor a metaphor; it is a cellular structure found in all living cells that synthesizes proteins by translating messenger RNA (mRNA). In literature, a simile is a figure of speech that compares two different things using "like" or "as," while a metaphor makes a direct comparison without those Words. Ribosomes serve a biological function rather than a figurative one.