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What is the specific cellular process for regulating the amount of the four DNA bases (adenine, thymine, cytosine, and guanine) that are present in the cytoplasm of a cell?

Basically, how do the cell's mechanical processes "know" that there are enough of these present in the cytoplasm for DNA/RNA processes to operate effectively?

From what I understand, DNA/RNA sequence production involves simply grabbing these out of the cytoplasm as they randomly pass near the sequence assembly protein.

As a side topic, but also important here, the cytoplasm is apparently just a random fluid containing all sorts of molecules flowing and diffusing in random directions via Brownian motion. I do not know if there is a specific direction cytoplasm flows around the inside of a cell, and if so, how the cell would manage to coordinate that either.

There does not seem to be a way for cell processes to "read" the proportional molecular contents of the cytoplasm to know if there is sufficient numbers of these present for proper cell function.

If there is a lack of any one of these four base molecules, DNA/RNA processes will slow or stop functioning, leading to systemic failure and potentially cell death.

If there are too many of any one of them, the cell could become so packed that nothing can move around and the cell's function is impaired. Possibly the cell wall could rupture if there are too many.

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    $\begingroup$ The specific cellular process that regulates nucleoside synthesis has chapters in books dedicated to it, but I think the question is still good and can be answered with an overview. You're side topic may be better off as an entirely different question. Diffusion is definitely important but, as a start, you can look up cytoplasmic streaming and cytoskeletal transport. $\endgroup$ – canadianer Mar 30 '17 at 21:26
  • $\begingroup$ @canadianer, nice mention of cytoplasmic streaming and cytoskeletal support: Brownian motion is only an approximation, and a very over-simplified one. However, keep in mind a whole different question may be needed to discuss the answer in the case of prokaryotes vs. the case of eukaryotes. Also, I believe you meant Your (not You're) $\endgroup$ – hello_there_andy Mar 30 '17 at 21:33
  • $\begingroup$ No no, I did mean "you are side topic", my grammatical mistakes came later ;) $\endgroup$ – canadianer Mar 30 '17 at 21:41
  • $\begingroup$ There is an area of biological science called Biochemistry that includes the processes by which cellular chemicals are interconverted — metabolism. You are correct in assuming that metabolism, including the pathways for the synthesis of nucleic acid precursors, is regulated, and in general this operates by certain intermediates acting as sensors, modulating the activity of key enzymes. Your question regarding the eight precursors of DNA and RNA synthesis is far too broad, and I have voted to close. I recommend Chapter 10 (Regulatory Strategies) in Berg et. al. (NCBI Bookshelf, online). $\endgroup$ – David Mar 31 '17 at 8:06
  • $\begingroup$ You would also benefit from reading the details of nucleic acid synthesis and that of its precursors, which are not free bases, but nucleoside and deoxynucleoside triphosphates. Again, there are chapters on this in the previously mentioned Berg et al. and other biochemistry texts. $\endgroup$ – David Mar 31 '17 at 8:16

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