All Peptide Hormones after Cell Function by Phosphorylation, while Essay

All Peptide Hormones after Cell Function by Phosphorylation, while Steroid Act by Alerting Gene Expression - Essay Example For instance, endocrine signaling involves the secretion of specific hormonal signals in the blood stream which are then distributed to other parts of the body. The first messenger molecule cannot pass through the target cell membrane, but instead are bound by specific receptors. Intracellular communication takes place when receptors activate secondary messengers or signaling proteins which convey those signals through chemical reaction to the nucleus of the cell (Marks, 2008). Proteins are the key signal processors in a cell. The incredible structural flexibility and chemical reactivity offers characteristic signal transduction property i.e., signals movement inside from outside of the cell, to all proteins. The input signals allow conformational changes in the structure altering the specific protein functions and cellular activity. Proteins capable of binding to a phosphate molecule are called phospho-proteins, and play a central role in the signaling pathway regulating various cel lular processes. Protein phosphorylation or phosphoregulation is a reversible process which regulates the protein function by covalent modification. To switch between phosphorylized and dephosphorylized states, specific kinase (tyrosine, serine/threonine) and phosphatase enzymes act respectively. Phosphorylation may either increase or decrease activity depending on specific type of enzyme. The affinity towards interacting cohort protein, enzymatic action, and subcellular localization and other functional changes are altered by protein phosphorylation (Goto, Kiyono and Inagaki, 2007). As a signaling molecule, proteins have a receiver and a transmitter module. In order to recognize and decode a specific signal, the receiver requires prior information for that signal which has to be either obtained or is genetically fixed. To coordinate signal and its exact implication, differentiation occurs exclusively in the receptor cells or target proteins. For instance, adrenaline hormonal signal has different meanings for different target tissues or target proteins control various functional consequences of phosphorylation. The intercellular signaling molecules including peptides, amino acids, amines and proteins cannot enter cell membrane and thus interact with receptors on the surface. The output signal transduction in receptor proteins results in a conformational alterations which are then differentiated by other signal transducing proteins along the pathway such as G-proteins. The chemical interactions taking place as a result of signal reception are not definite sequences, but rather diffused and complex excitation patterns (King, 2012). The hormones secreted by endocrine tissues get attached to particular plasma carrier proteins and composites are then distributed to distant parts. The receptors in the responding tissues have very high affinity for hormones and regulate metabolism of target through a coupled process. The receptors for amino acid and peptide hormones are mostly present on the cell membrane. Signal transducing receptors are classified into receptors with ability to enter cell membrane such as tyrosine kinases, tyrosine phosphatases and serine/threonine kinases, serpentine receptors which are coupled such as adrenergic and odorant receptors, and nuclear or intracellular receptors such as steroid

Reasons why illegal immigranst who are already living in this country Research Paper

Reasons why illegal immigranst who are already living in this country should be given citiznship - Research Paper Example Recently, debates on immigration have focused on the American South due to its border with Mexico where Latino immigrants get a passage into America. The political division has not helped to bridge the political opinions of opposition sides. In this assignment, I argue that despite the ongoing heated political debates, illegal immigration ought to be granted American citizenship. Historically, the American nation has been known to be a haven for immigrants to the extent that it is now a European descendant’s majority. Prior to the September 11, 2011 attacks on America by foreign nationals, there was little talk of racial profiling at airports. Entry to America became difficult for all immigrants with additional security checks instituted for fear of attacks, therefore, the ensuing debate on illegal immigration (Wise 26). Security is paramount for the stability of the American nation. Nevertheless, racial profiling is an infringement on the civil rights of human beings since it focuses on certain ethnic groups. The impact of European descended Americans in shaping America’s course cannot be disputed. However, the argument that America ought to be identified with regards to being â€Å"white† is flawed (Wise 32). America is a melting pot with people from diverse cultures, religion and ethnic backgrounds. The contribution of the multiplicity of people cannot be ignored. Granting of citizenship to illegal immigrants would be a humane act devoid of racial overtones. National security depends less on the number of illegal immigrants. This is because foreign nationals and terrorists do not have to be American residents to commit crimes. The rigorous security checks instituted mean that it is harder for foreign terrorists to gain citizenship. With proper checks in place, illegal immigrants are granted citizenship if there is reasonable belief that they pose