Please answer the following biochemistry questions completely, thanks! In-Class
ID: 213270 • Letter: P
Question
Please answer the following biochemistry questions completely, thanks! In-Class Assignment 3 19. A in in tonstreameffect of epinephrine signaling is the release of Ca. into the cytoplasm. This release turn stimulates cellular proces ses through calmodulin. Describe the signaling pathway IN DETAIL ng with epinephrine and ending with the release of Ca into the cytoplasm. In your explanation make sure to demonstrate your knowledge of G protein preferred. (5 pts) activation. List formatting is 20. It is a common misconception that insulin "breaks down glucose". Explain what the true role of insulin is in the body. In your explanation make sure to demonstrate your knowledge of tyrosine kinases and their role in reducing blood glucose levels. (5 pts)Explanation / Answer
Q19). Signalling pathway of epinephrine:
Epinephrine is an agonist of the G-protein coupled receptors. G-protein coupled receptors are the transmembrane receptors present on the cell membrane, they are also called metabotropic receptors. They contain three subunits namely alpha, beta, and gamma. Binding of agonist or antagonist make changes to the alpha, beta and gamma trimmer that triggers intracellular changes. Intracellular changes are triggered by three types of secondary messengers namely cyclic AMP, inositol triphosphate, and calcium.
Alpha unit is bound to one GDP molecule, binding of an agonist at receptor site causes replacement of GDP with GTP, and dissociation of the alpha unit from the beta-gamma unit. This is followed by a series of reactions mediated through secondary messengers that result in effector activation, again GTP is replaced with GDP, alpha-beta-gamma trimer re-associates. They produce effects within minutes.
IP3 increases the calcium release from endoplasmic reticulum by acting through IP3 receptors. DAG diffuses through the plasma membrane and activates protein kinase C. PKC is present in many isoforms, which is activated by raised intracellular calcium levels.
Calcium activates calmodulin protein by allosteric binding and thus activates calcium-calmodulin dependent kinases. The calcium-calmodulin complex activates the myosin light chain kinases by phosphorylation, which causes muscle contraction.