13 votes
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Why do Hot/Cold drinks taste sweeter once returning to room temperature?

Generally, cold suppresses sweetness. As an example, consider soft drinks that are usually served cold: they taste sweeter when warm (like you said with your examples of drinks). Our taste receptors ...
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  • 2,573
9 votes

Why do we get sleeply after we eat?

After we have eaten... the maximum blood supply is transferred towards the digestive system so that digestion is done, and therefore the brain to does not get adequate blood supply. Am I right about ...
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8 votes

What are the effects of removing CD4 receptors?

The CD4 receptor is vital for the proper functioning of the immune system. It is found not only on T-Lymphocytes, but also on macrophages and dendritic cells. Its function on T-cells is to stabilize ...
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  • 4,945
8 votes
Accepted

How precisely can we sense temperature differences?

Short answer Temperature differences of 0.02 degrees Celcius can be distinguished, dependent on various factors including experimental conditions and bodily location. Background The ability to ...
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6 votes
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The mechanism of mechanoreception?

A mechanical stimulus can act on a tissue with elastic and viscoelastic properties in two ways [1, 2]: distort the cellular membrane which leads to opening of ion channels. create tension on the ...
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  • 7,077
6 votes

What structural features make a molecule a potent opioid receptor agonist?

Specific parts — moieties — of an agonist molecule bind to the receptor protein, causing the receptor to change shape, which in turn initiates a signaling pathway inside the cell. Some agonists are ...
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6 votes

Why is ACE2 not used as drug against covid?

There's a Cell pre-print by Monteil et al. (DOI: 10.1016/j.cell.2020.04.004) which argues that human recombinant soluble ACE2 protein can competitively bind to SARS-CoV-2 virus and reduce its ability ...
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6 votes
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Same target receptor different mechanism of action?

Not necessarily! Biased agonism It's reasonable to start with an expectation that agonists at the same receptor have the same effect, but that's not necessarily true due to biased agonism. Biased ...
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6 votes

How do G proteins move?

Interpretation of the Question The question asks how the G-protein α- and βγ-subunits move, but does not state the context or circumstances of the movement. I assume that the question is, in fact: ...
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5 votes
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How is adrenaline (also known as "epinephrine") a ligand?

The definition of "ligand" in the question, "a molecule or ion which donates a pair of electrons to a central transition metal ion in a complex" is clearly a more technical 'chemistry-type' of ...
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5 votes
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Are resonances the reason receptors work?

Photoreceptors themselves dont act as oscilators, a single receptor is either 'on' or 'off' - it does not respond differently to different wavelenghts. Humans have Trichromatic vision, which means ...
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  • 4,296
5 votes

How are the receptors in the thalamus weakened/shut down during sleep?

Sleep research is a big field and the answer to your question can take many forms and fill libraries. Having said that, it is not so much inhibition of the thalamus per se, but a change in firing ...
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4 votes
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How does receptor downregulation/upregulation work?

Both internalization (sometimes with degradation) and changes in gene expression can occur; the circumstances leading to the down regulation determine which (or both). It isn't necessary for receptors ...
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4 votes
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Receptors for red and far-red light in plants: Shade avoidance

As far as I know there are 5 receptors for far-red and red light which are the phytochroms(phyA-phyE) Its all about the ratio between red and far-red light. Each phytochrom has an inactive(PR) and ...
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  • 164
4 votes
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Does the dissociation of serotonin receptors and their ligands really take hours?

That paper is describing the binding between the 5HT3 receptor and some high-affinity ligand, not serotonin. Numbers of serotonin probably vary according to the precise receptor (species, subunits, ...
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  • 36.7k
4 votes

Is there a specific mechanism for the delivery of pain medication?

Short answer No, orally taken painkillers act systemically. Background Taking a painkiller orally results in the drug being taken up into the bloodstream by the digestive system. From there it can ...
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  • 51.2k
4 votes

Trypsin and Cell Surface Receptors

Yes. Trypsin cleaves proteins and can do so quite indiscriminately if left on for very long. Trypsin is primarily used to cleave the proteins that cells use to adhere to each other and the plate in ...
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  • 1,309
4 votes
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Is there a reason for the lack of full RTK structures?

Large proteins are challenging for NMR: the more amino acids, the more peaks one has to assign. Peak overlap is also more likely the more amino acids you have, making assignment difficult. Some NMR ...
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  • 705
4 votes

Additive property of taste

I would classify the neurological phenomenon of "taste" or "tastyness" as an emergent property (1), and therefore synergistic (i.e. not adequately explained simply by additive effects). For example, ...
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  • 4,551
3 votes

Neuroscience behind the crash

The "crash" effect is typically perceived as a deterioration in affect. With drugs, this deterioration happens as the drug is cleared from blood circulation, particularly cerebral circulation. With ...
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3 votes

Redheads and pain receptors

I think it's best to break this question up in to two parts: What mutations account for red hair and fair skin in humans How might these same mutations affect pain sensation MC1R variants & red ...
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  • 766
3 votes
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Why are skin tactile receptors considered to be phasic receptors?

Short answer Slowly adapting mechanoreceptors in the skin mediate the perception of static pressure stimuli, while rapidly adapting skin receptors mediate swiftly changing (e.g., vibratory) stimuli. ...
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3 votes

Influenza infections and drug design

It's not that people didn't want to use hemagglutinin as a target for antivirals, it's that they haven't been able to get the antivirals through the approval process yet. There are a number of ...
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3 votes

How do we know that selective agonists are indeed selective?

Unfortunately, it's really hard in the general sense. Even for FDA-approved drugs with well-characterized mechanisms of action, the binding profiles are incomplete. For GPCRs, it's you can run your ...
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2 votes

Is there a specific mechanism for the delivery of pain medication?

Most NSAIDs derive their analgesic effects from inhibit the cyclooxygenase (COX) enzymes that produce the prostaglandin-H2 precursor to the prostaglandins that sensitize neurons to pain. Edit: With ...
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  • 1,771
2 votes

Toll Like Receptors Vs Toll Receptors

In Drosophila, Toll receptors are used during embryonic development as well as innate immunity. See The Drosophila Toll Signaling Pathway by Valance, et. al. Toll-like Receptors are pattern ...
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  • 4,945
2 votes

Do antagonist-receptor complexes get absorbed into the cell?

When a neurotransmitter, like serotonin, binds to it's specific receptor, the ligand-receptor complex is not phagocytosed. Picture the human cell membrane and think of the serotonin receptor like a ...
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2 votes

What are the effects of removing CD4 receptors?

I think it's deathly important to note how critical CD4 is for the activation of T-helper cells, and thus a myriad of downstream immune cells such as B cells: When an APC presents an antigen through ...
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  • 8,041
2 votes
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Does anyone know of any resources that detail an extensive number of receptor types, their effects, and signalling pathways?

From the comment section: The IUPHAR database is one of the most extensive database for receptors and ligands. It also contains a lot of additional information and direct references to the literature....
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