The TCR and BCR Are Each Composed of Two Modules

question 19

Essay

The TCR and BCR are each composed of two modules, an antigen-binding module and a signaling module; furthermore, in each case, the two functional modules are encoded by distinct polypeptides. In addition, the tyrosine kinases that initiate antigen receptor signaling are also separate proteins from those of each receptor. This is a different strategy for receptor signaling than the case of receptor tyrosine kinases, where the enzyme is an intrinsic component of the ligand-binding receptor protein. Name one advantage of this organization of the TCR and BCR that accounts for the expression of ZAP-70 and Syk, as well as ITAM-containing immunoreceptors, in many different subsets of immune cells.

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Definitions:

Overhead Rate

A measure used to allocate indirect costs to produced goods or services, calculated as overhead costs divided by the allocation base.

Job Order Cost System

An accounting system that accumulates costs by individual jobs when the products or services are distinguishable from each other.

Time Tickets

Documents or electronic records used to track the amount of time an employee spends on a specific job or project.

Job Cost Sheets

Documents that track the direct materials, direct labor, and manufacturing overhead for a specific job, used in job costing systems.