New answers tagged biochemistry
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The mammalian target of rapamycin (mTOR) is a Ser/Thr protein kinase that functions as an ATP and amino acid sensor to balance nutrient availability and cell growth. When sufficient nutrients are available, mTOR responds to a phosphatidic acid-mediated signal to transmit a positive signal to p70 S6 kinase and participate in the inactivation of the eIF4E ...
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There are both chemical and electrical synapses in many organisms. The electrical synapses are called gap junctions.
As you point out, the primary advantage of gap junctions is their speed, and they are commonly used in systems involving defensive reflexes.
However, as AndroidPenguin indicates, chemical synapses allow for greater computational abilities ...
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This is the coolest part. Those synapses are the reason the brain is so complex! Basically you've got the first part right, the neurones are quicker and they transmit messages from one end to the other. The other thing you have to do is analyse and calculate. Signals from multiple neurones feed into a single neurone using a chemical synapse. Similarly the ...
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please go through the journal: S. Jo, K. Park, Biomaterials 21 (2000) 605-616.
The time and temperature probably helps to hydrolyze, formation of hydrogen bond and covalent bond formation. Hope this paper will help you.
Good luck!
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Here is a possible answer given by this paper:
http://www.ncbi.nlm.nih.gov/pubmed/16794952
or
http://www.math.unl.edu/~bdeng1/Papers/DengDNAreplication.pdf
It gives a Darwinian explanation to the question. It approaches the problem from Claude Shannon's theory for communication. It treats DNA replication conceptually and mathematically the same as a data ...
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This is one of my favorite charts demonstrating the complexity of amino acid properties:
http://www.jalview.org/help/html/misc/aaproperties.html
Histidine is probably the most complicated amino acid in this regard (just compare how many circles it falls into). But don't undersell Cysteine and Methionine; those sulfurs exhibit some surprising behavior, ...
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I am wondering why it is not mentioned at all in basic text books such as Lehninger?
Books are not flawless.
Another reason I am a little confused is, if protonation doesn't harm the aromatic nature, > then why is histidine such a weak base?
Pyrolles have a weak basicity because of delocalization of the electron lone pair of nitrogen. It is the ...
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The imidazole ring in histidine is indeed aromatic. But an aromatic amino-acid is not usually defined as "an amino-acid with an aromatic ring". Rather, they are usually defined by common chemical properties, such as high absorption at 280nm, or better their common metabolic pathway.
Histidine as a stand-alone amino-acid is a weak base, but this is mainly ...
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As far as I am aware there are various regulatory mechanisms (allosteric regulation, hormonal control) in place to minimise futile cycling by ensuring that phosphofructokinase (glycolysis) and fructose 1,6 bisphosphatase (gluconeogenesis) are not both active at the same time.
See this Wikipedia article for a starting point.
The precise regulation of ...
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There are various parameters that describe change of seasons such as day length, temperature, humidity. But it can be assumed that most of these parameters ultimately depend on one parameter- day length.
The response of plants towards the length of day/night cycle is called photoperiodism (which dictates spring flowering).
This article explains the effect ...
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What biochemical molecule viewer allows for changes in amino acids and resulting tertiary structure?
If I understand what you're attempting to accomplish, as David said, this is a vigorous area of study in structural biology. I'll start by saying that a single amino acid substitution will often make virtually no difference in a structure, but there are proteins where a couple substitutions will convert an all alpha-helical protein to all beta-sheet, so I'll ...
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