13 votes
Accepted

Why is insulin given in type 2 diabetes?

Isn't it illogical to give more of insulin for a deficit amount of receptors? Seems like there is some confusion in the definition of type-2 DM itself. According ...
another 'Homo sapien''s user avatar
11 votes
Accepted

How do chameleons signal cells to change color?

As said by @dblyons, there has not been a lot of research (biochemical) on chameleons. So, the exact part of mechanism that you're looking for is still not understood. However, we have recently caught ...
another 'Homo sapien''s user avatar
9 votes

Why is insulin given in type 2 diabetes?

This is true for the beginning of the disease. As a reaction to the reduced sensitivity of the cells in the body to insulin (and thus less uptake of glucose from the blood and a resulting ...
Chris's user avatar
  • 51.6k
9 votes
Accepted

How do DNA, enzymes, hormones etc. reach their proper cellular locations?

The answer given by Sadegh gives a general correct broad view. But one part of the puzzle is missing, which is molecular recognition. Molecules bind to each other via physical/chemical interaction ...
alec_djinn's user avatar
  • 3,108
8 votes

What is the difference between a cytokine, a hormone and a protein hormone?

Parts of the answer are in the text that you provide yourself. But I shall try to add where i can. What do each of these three terms [hormone, cytokine and protein hormone] mean and how are they ...
Jonas's user avatar
  • 533
7 votes

How do cells relocate transmembrane proteins from one side of the cell to the other? Is it possible?

The breakdown and reassembly of proteins is a ubiquitous process within cells, and yes this is expensive but transport is expensive, too, and recycling has the added benefit of dealing with proteins ...
Bryan Krause's user avatar
  • 45.7k
7 votes

How do DNA, enzymes, hormones etc. reach their proper cellular locations?

It's both simple and complex. The simple answer is Brownian motion. All the particles in the cell do have mobility which is related to their mass. A small particle like a soluble enzyme undergoes ...
Sadegh Ghasemi's user avatar
7 votes

What do the the different arrowheads mean in a cell signalling diagram?

Arrowhead interpretation As I said in my comment and to add to @AlwaysConfused's answer, the arrowhead is a promotion, and flathead is an inhibition. Typically, any other notation such as dotted lines ...
James's user avatar
  • 11.3k
6 votes

Where and how is information about pathogen immunity stored in a cell?

All the body does is produce a ton of cells that can recognize single antigens. Each time you encounter pathogens, some of these naïve cells contact antigen that can activate them. The activated clone ...
CKM's user avatar
  • 8,109
6 votes

Why is insulin given in type 2 diabetes?

Insulin is a "last resort" treatment for people with Type 2 diabetes—partly due to the unpleasantness of injections, but partly due to the fact that high insulin levels can worsen insulin ...
Artelius's user avatar
  • 191
5 votes
Accepted

Is every neurotransmitter receptor an ion channel?

is every neurotransmitter receptor also an ion channel? No. There are two general types of receptors for neurotransmitters, ligand gated ion channels and receptors that activate second messenger ...
De Novo's user avatar
  • 8,791
5 votes
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How do cells relocate transmembrane proteins from one side of the cell to the other? Is it possible?

Transmembrane proteins can move laterally through the plasma membrane (see fluid mosaic model) and this movement can be actively directed along the cytoskeleton. The following paper is the most ...
canadianer's user avatar
  • 17.7k
5 votes
Accepted

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 ...
Guillaume's user avatar
  • 715
4 votes
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How do we know if a neuron is inhibitory or excitatory?

In my naive understanding, a neuron was inhibitory or excitatory depending on the neurotransmitter it releases onto its postsynaptic partners. This is mostly correct. What remains a question is what ...
Bryan Krause's user avatar
  • 45.7k
4 votes
Accepted

What are " temporal kinetics"?

Temporal kinetics does not refer to the kinetics of kinase phosphorylation reactions and, since it is not standard terminology, you likely wouldn’t find its meaning in any textbook. The authors of the ...
canadianer's user avatar
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4 votes
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Receptor tyrosine kinases: What is meant by basal phosphorylation of the receptor?

I think these excerpts are helpful in understanding the authors' use of basal, both in reference to insulin levels and insulin receptor phosphorylation -- As expected, insulin receptors from ...
acvill's user avatar
  • 8,296
3 votes
Accepted

Specific examples of signalling pathway using logical 'OR' and 'AND'?

There are thousands of examples, here I list just a few. 1) Macrophage activation. This is a complex case with many proteins acting as AND/OR. The following paper depicts a nice scheme that helps to ...
alec_djinn's user avatar
  • 3,108
3 votes

How do DNA, enzymes, hormones etc. reach their proper cellular locations?

Shortly, understanding a process called molecular recognition (as stated by @alec_djinn) under crude biological environment would answer all your questions. Before explaining answers for your ...
Science123's user avatar
3 votes

What do the the different arrowheads mean in a cell signalling diagram?

The "normal" (green here) arrowheads stand for a positive effect of the upstream factor or protein on the process or protein it points to. For instance, it means amino acids activate TORC1. Instead, ...
allepasse's user avatar
  • 341
3 votes
Accepted

What does it mean to "nucleate multi-protein complexes"?

Here nucleation has a rather physical meaning. mTOR acts as the starting assembly point of the complex.
KaPy3141's user avatar
  • 1,597
3 votes
Accepted

At what calcium concentration does the Sodium-Calcium Exchanger (NCX) "turn on"?

I could not find the $K_d$ of NCX proteins in KEGG BRITE, BRENDA, SuperTarget, DrugBank, Uniprot, or PDSP Ki databases... (Also, I cannot understand the use of the word 'relevant' in the question you ...
Amirreza Mousavi's user avatar
3 votes
Accepted

The quality of binding sites?

Quality is most likely related to how tightly RNAp binds to conserved sequences in the promoter, and that is related to how closely the actual sequences themselves are to RNAp's "most-preferred&...
MattDMo's user avatar
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3 votes
Accepted

Molecular Signaling: Why is it more difficult to study membrane-bound signaling molecules compared to soluble ones?

Secreted/soluble/extracellular signaling molecules you can synthesize/purify externally and dump them on some tissue or cells to see what they do. You can't really do the same with signals that are ...
Bryan Krause's user avatar
  • 45.7k
3 votes

Membrane Potential Question

Usually we use the Goldman Equation when calculating membrane potential with multiple ions and the Nernst equation for calculating reversal potentials for individual ions. Try out the Goldman Equation ...
Bryan Krause's user avatar
  • 45.7k
2 votes

How is receptor production (recycling) regulated?

So, what is causing the higher degradation than usual? Is it the lack of the materials required to produce the receptor? Lack of materials is almost never the reason. Receptor turnover is actively ...
WYSIWYG's user avatar
  • 35.6k
2 votes

Cell biology books

BOOKS If you want to learn about cells in detail from scratch to advanced level I recommend you two books: Molecular Biology of the Cell, 6th Edition. 2014. Bruce Alberts, Alexander Johnson, Julian ...
l..'s user avatar
  • 131
2 votes

Models of quorum sensing for multi-agent systems

Since the accepted answer is nearly a decade old, I'm adding a new answer to address a recent piece of research that presents a good framework for modeling quorum sensing over small distances.1 First, ...
acvill's user avatar
  • 8,296
2 votes

Can a protein kinase phosphorylate both a threonine and tyrosine residue?

Ony a few protein kinases can phosphorylate all three amino acids — these are classified as dual-specific kinases (EC 2.7.12.1). Examples are APK1 from Arabidopsis or MEK kinases in mammals. As with ...
Ashafix's user avatar
  • 695
2 votes

How do chameleons signal cells to change color?

This is a good question and... kind of remarkable because I don't think there is a specific body of literature regarding chameleons. Generally though, vertebrate skin cells responsible for color (...
dblyons's user avatar
  • 382

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