Diderot
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"The essence of cellular life is regulation: The cell controls how much and what kinds of chemicals it makes; when it loses control, it dies."
In respect to the demand for fine-tuned regulation I'm still struggling with the concept of diffusion as a transport system.
What do you think? Am I getting closer to understanding?
In respect to the demand for fine-tuned regulation I'm still struggling with the concept of diffusion as a transport system.
Earlier in this thread I wrote:Darwin123 said:Physicists and biologists think of diffusion as one specific type of transport. ... Diffusion is the transport that is characterized by "random" motions of the molecules. [D]iffusion dominates within an organelle.
Diderot said:I'm trying to incorporate these speeds in my understanding of the cell. According to Ken Shirrif these speeds explain a lot: “Watching the video, you might wonder how the different pieces just happen to move to the right place. In reality, they are covering so much ground in the cell so fast that they will be in the ‘right place’ very frequently just by chance.” This seems debatable to me. If in a workshop all the parts of a car are floating around it’s hard to imagine that a car will be assembled. ...
If the different bits have the possibility to form all sorts of chemical bonds the only result can be chaos. Random movement of Lego parts cannot explain a complex Lego car. So the different bits must all be highly specified and have just one possibility to fall into place.Simon Bridge said:[T]hough everything is moving fast, the interactions are even faster. On top of that, the different bits have a range of ways they attract and repel other bits...
Another thing that is necessary is sequence of assembly. So highly specified part A must have just one possibility B at moment C and highly specified part A’ must have just one possibility B’ at moment C’ … etc.Simon Bridge said:To use your analogy of car assembly - it's like the situation where different workers and parts arrive at different times ... when someone sees the right part, they put it in the car. You can build a car that way - in fact, hobby auto-mechanics (restoring a car for eg) often works like that...
What do you think? Am I getting closer to understanding?