Central Dogma of Molecular Biology

“Cellular information has allowed routes and one key boundary: a protein does not write its sequence back into DNA.”

01 / PLAINLY

What it means, plainly

The central dogma organizes transfers of sequence information among DNA, RNA, and protein.

02 / CONTEXT

A little more

DNA can be copied and transcribed into RNA; RNA can be translated into protein and, in some systems, copied into DNA. The central rule bars transfer of sequence information from protein to nucleic acids.

03 / WHY IT MATTERS

Why it matters

It maps replication, transcription, and translation without collapsing them into an oversimplified arrow with false exceptions.

04 / EXAMPLE

A familiar example

A retrovirus copies RNA into DNA through reverse transcriptase; that route fits the original formulation.

05 / LIMIT

What it does not mean

It does not merely say DNA→RNA→protein or deny retroviruses, regulatory RNA, or prions.

06 / NOTICE

Notice it in your day

Draw DNA, RNA, and protein and mark demonstrated transfers; then identify the boundary that is not crossed.

FINAL NOTE

The idea worth keeping

Ask what kind of information moves between which molecules before calling a process an exception.

QUESTIONS / 02

Questions people still have

Does reverse transcription break the central dogma?

No. RNA-to-DNA transfer was included; the relevant boundary begins with protein sequence.

Do proteins have no influence on genes?

Proteins regulate genes and chemistry, but that influence does not copy protein sequence back into DNA.