Joined: 02 Jan 2007
|Posted: 05.05.2018 20:37 Post subject: Step is indeed the pressure, and nothing but the pressure.
|Viral infection a matter of simple physics
"A phage consists of a head and a tail. The tail acts as an injection needle that can penetrate the cell membrane. The DNA is stored in the head of the phage, and exerts a pressure of around 60 bar. That is equivalent to 20 times the pressure in a fully inflated car tyre, or the pressure at 600 meters under water. Once the tail of the phage penetrates the cell, the 'valve' opens and the DNA is injected into the cell at high speed. This quickly releases the pressure of the DNA inside the phage. An outstanding question facing the researchers was therefore: what forces the last portion of DNA to enter the cell once the pressure has been released?
In an experiment, the researchers determined the speed of the DNA transport from phage to cell in phages in which only the initial pressure was different. In both cases, the researchers observed two distinct steps. Calculations confirmed their suspicion that the driving force in the first step is indeed the pressure, and nothing but the pressure."
Olemmeko löytämässä itse itsemme? Yhdistyvätkö eri uskonnot ja tiede jo meidän aikana?