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4

It may be important to consider the developmental stage of the "female body" as well. For instance, organizational vs. activational hypothesis--injecting testosterone during a critical period during development (it can be pre-natal, or during puberty) could produce permanent changes in secondary sexual characteristics and sex-specific behaviors; however, ...


2

Steroid hormones produce a slow response because they do not have secondary messenger It's true that steroids don't have secondary messengers because they don't need them - they can go directly into a cells nucleus and affect transcription there. This wouldn't slow down the response by much, however. Slow response is due to lack of cell membrane receptors ...


5

The quick answer is that only certain cell types express the required steroid hormone receptors that are necessary to induce signaling and gene regulation when bound to their target steroid hormones, like estrogen, testosterone, cortisol, etc. If no receptor is present, the steroid doesn't effect any change. The second part of the answer involves the ...


1

There are some inhibitors in the cell, which have specific effects on signal transduction. These are mostly second messengers (like cAMP, cGMP, calcium ions, inositol 1,4,5-trisphosphate and others), which are then able to diffuse relative fast to other proteins. There they can either amplify a signal or cause inhibiting processes to start which then ...


1

It is both, a and b. The JAK-STAT-Pathway sits below the Erb-receptor and is therefore giving the signal from mutated Erb down the signalling cascade. Besides that a permanent active version of Jak2 has been found which also permanently activates this pathway. Both are contributing to cancer. See this two articles: Molecular Pathways: JAK/STAT Pathway: ...


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i thnk it is MAP Kinase pathway b'coz RAS is a protein involved in this pathway and mutation in it lead to permanent attachment of GTP leading to cell proliferation causing carcer


2

This is a short review about the issue and not complete. This and the earlier answer are not proofs of the link between the two proceses. To investigate this better, I think it would be much easier first to narrow the case to testosterone and energy homeostasis (Embryology; or better formulated research case) catabolism and anger anger and aggressive ...


5

Brain's main energy source is glucose. It uses about 20% of total glucose [1]. Brain hypoglycemia causes depressive-like behaviors in mice through adrenergic pathways [2]. When it comes to humans, here is a study that claims low glucose leads to increased aggression in married couples (see this too): Self-control requires energy, part of which is ...


4

This is mostly because of the nature of the amino acids. You need to have a Hydroxy-group in the sidechain of the amino acid which is the point where the phosphogroup is attached. Since this process needs to be reversible, this can only happen here. See the image below (from here) about the chemical structure: In eukaryotes not only these three are ...


4

Phosphorylation requires a nucleophile and hydroxyl oxygen acts like one. Serine, theronine and tyrosine get phosphorylated on the free $OH$ group in their side chains. Nitrogen, in some cases also can act as a nucleophile. In case of histidine, the imidazole nitrogen is phosphorylated during bacterial chemotaxis signaling. As far as I know eukaryotes do ...


2

Those residues are phosphorylated because they have a free hydroxyl group available to be bonded to a phosphate. Many other resides can be modified, like acetylation of lysines, but only those residues are chemically compatible with reversible phosphorylation.


3

For this specific question, let's divide the cells into two categories: Cells that rarely "navigate" are the cells that are connected to give the tissue its mechanical properties. How do these avoid an "adverse stimulus"? Well, they don't avoid it. But if that stimulus "harms" cells they react in some way: if the cell is destructed by the pathogen, it ...



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