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Physiology & Medicine / Re: Does masturbation promote fertility?

« on: 21/06/2017 16:48:46 »

my understanding is that yes, it does (as long as you refrain within the 48hr period prior to copulation).  more importantly, it also reduces the risk of prostate cancer.

2

Physiology & Medicine / Re: Do genes and DNA respond to musical vibrations?

« on: 21/06/2017 16:46:49 »

I would assume that all of the physiological responses to music happen at the receptor signaling level.  These responses COULD conceivably lead to temporary changes in gene EXPRESSION, but not ACTUAL genetic alterations.  I suppose that in the case of EXTREME (and likely repeated) exposure to a certain stimulus like music, epigenetic changes could occur that would be more permanent, but the DNA itself would still be unaltered.

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Physiology & Medicine / Re: What is the physiological function of lipid rafts?

« on: 12/05/2017 15:38:37 »

lipd rafts serve to sequester different signaling complexes to different physical proximities in the cell.  For example, if a cell needs to change shape, it is not enough to simply cue the signal for actin polymerization, the cell needs to dictate WHERE that actin polymerization is to take place.  By re-arranging the organization of various lipid species within its membrane structures, a cell can determine WHERE a given activity will take place. In the case of actin polymerization, some of the signaling proteins are attracted to a certain species of lipid and thus are sequestered to regions where this species has been concentrated and/or generated at a higher rate.  When these multiple signaling proteins come into proximity with each other (as a result of being recruited by the lipid rafts) they activate each other and actin elongation occurs at the precise spot where the lipid content was altered.

4

Physiology & Medicine / Re: Why don't scars disappear as tissue is replaced over time?

« on: 12/04/2017 18:00:03 »

I can say from my own research that we see an initial accumulation of senescent cells at the site of a healing wound/forming scar tissue, but these cells most definitely disappear over time (matter of weeks, at least in mice) indicating that the cells in that part of the tissue ARE being turned over, even if that structure of the scar remains.

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Cells, Microbes & Viruses / Re: How do the proteins not become this giant mess of tangled threads?

« on: 11/04/2017 15:27:46 »

Two factors that the original question failed to consider:

1) proteins fold AS they are being translated rather than waiting for translation to finish and then folding all at once.  Therefore, you don't have all these long strings of amino acids just hanging around.

2) While cells are very small and compact, proteins are even smaller, so they have a reasonable amount of room in which to translate and fold.

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Cells, Microbes & Viruses / Re: How robust is the evidence for the effect of the microbiome on the brain?

« on: 11/04/2017 15:13:06 »

I guess I'd want to see exactly what claims she is referring to (and what studies those claims came from) to really be able to comment.  Lots of great new information coming out in recent years as to the importance of the microbiome as it relates to SO many aspects of our physiology, but I can't say I've seen anyone claim that our gut bacteria "thinks" for us.  I guess that would give a new meaning to the phrase "go with what your gut tells you".