how Life works

Life’s story begins with DNA, the molecular archive of information. Its sequence encodes instructions that guide every process within the cell.

Through transcription, DNA gives rise to RNA, a working copy that carries genetic instructions into the active world of the cell.

RNA is translated into proteins, the molecular machines that fold into precise shapes and perform the chemistry of life.

Networks of proteins create traits, the phenotype, which defines how an organism looks, behaves, and survives.

Finally, the phenotype interacts with the environment, which then indirectly influences the DNA via natural selection, completing the cycle of life’s interactions.

But, the reality is not so simple

Consider the connection from DNA to Proteins in Humans, which is thought as comprising of linear and one-to-one transformations.

Firstly, not every gene in human genome is active. Most of the genome stays silent in any given context. Expression depends on regulatory networks, chromatin state, and signals coming from other molecules and the environment.

A single gene can give rise to many transcripts through alternative splicing. Splicing choices aren’t random and are guided by proteins and RNAs that themselves come from other genes, forming feedback loops within the system.

Not all transcripts are translated. Many RNAs act as regulators, influencing which genes are turned on or off. RNA molecules control genes, creating layers of reciprocal influence rather than a one-way path.

After translation, proteins are reshaped by post-translational modifications (PTMs) leading to many proteoforms. These modifications respond to internal and external cues and in turn feed back to regulate transcription, signaling, and metabolism.