A protein kinase that is specific to the amino acids serine and threonine is known as a mitogen-activated protein kinase (MAPK or MAP kinase; also known as a serine/threonine-specific protein kinase).
<h3>Mitogen-activated protein kinase :</h3>
A small number of cell surface receptors can ultimately generate a large intracellular response due to activation of kinase cascades.
In order to trigger an appropriate physiological response, such as cellular proliferation, differentiation, development, inflammatory reactions, and death in mammalian cells, MAPK pathways relay, amplify, and integrate information from a variety of stimuli.
Tyrosine phosphorylation, specifically numerous tyrosines on each RTK in the dimer, is how cross-linking triggers the tyrosine kinase activity in these RTKs. The term "cross-phosphorylation" refers to this action.
The activation of a MAPKKKK or MAPKKK by stimulation of plasma membrane receptors is the initial stage of signal transduction. The MAPKKK then phosphorylates two serine or threonine residues in the S/T-X5-S/T (X is any amino acid) motif of its activation loop, activating a downstream MAPKK.
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SPJ4
Fish are cold-blooded or poikilothermic, meaning that their body temperatures vary with the surrounding temperature. During the cold of winter fish become less active. They find little pockets out of the way of fast moving water where they can stay still and conserve energy.
The answer is A. utilize ducts to release their secretions.
Exocrine glands are glands that secrete their products into ducts, they are the counterpart of endocrine glands which release their products into the bloodstream. Typical exocrine glands include: mammary glands, sweat glands, salivary glands, and many glands of the digestive system.