Cell Metabolism - Bioprocess Engineering: Kinetics, Biosystems, Sustainability and Reactor Design - page 475

Cells operate with an analogous system. Figure 10.2 displays the central dogma of biology,
further exemplifying from Fig. 10.1 . Information is stored on the DNA molecule. The stored
information can be replicated directly to form a second identical molecule. Further segments
of information on the molecule can be transcribed to yield RNAs. Using a variety of RNAs,

Protein

Lab

DNA RNA

Viruses
and/or
Lower life forms

Viruses

FIGURE 10.1 The flow of biological information in living systems.

DNA

DNA

Replication
DNA ⇒ DNA

DNA Polymerase

Reverse
transcription
RNA viruse

Transcription
DNA

RNA Polymerase

⇒ RNA

Protein binds to regulate
transcription

Translation

Ribosome

Protein

FIGURE 10.2 The central dogma is the primary tenet of molecular biology, which applies to all living organisms.
DNA serves as the template for its own replication, as well as transcription to RNA. The information transcribed into
the RNA can then be translated into proteins using an RNA template. The information on the DNA molecule is time
independent at a timescale much longer than RNA, then protein. The information exists in the form of RNA andmore
so protein molecules depends on the history and environment of the cell and is more clearly time dependent. Some of
the proteins interact with DNA to control which genes are transcribed in response to the environment.