This mRNA leaves the nucleus, and is translated in the ribosomes into specific protein or enzyme. (iv) Influence muscle contraction and relaxation. (ii) Increase secretion and release of stored hormones (i) May influence membrane permeability to amino acids, water and ions The enzymes and other proteins produced by this process: Active protein kinases can also activate ribosomal protein synthesis. The process of phosphorylation can also change the configuration and properties of other specific proteins which may be structural or membrane proteins. Protein kinases promote phosphorylation of specific enzymes which may activate or inactivate other enzymes. c-AMP is degraded to 5′-AMP by an enzyme, phosphodiesterase. Cyclic AMP activates one or more of the c-AMP dependent protein kinase enzymes within the cell. This enzyme acts upon ATP in the presence of Mg ++ to produce cyclic AMP and inorganic pyrophosphate. In the second mechanism, binding of the hormone with the surface receptor activates membrane bound adenyl cyclase enzyme. Opinions differ regarding the membrane permeability alterations are primary or secondary. Other hormones, which alter membrane permeability are growth hormone, glucocorticoids, glucagon, vasopressin, testosterone and oestrogen. For example, insulin controls the entry of glucose into the cells by means of a special transport system. Entry of ions, glucose and amino acids into the cell in dependent on membrane permeability which is controlled by hormones.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |