Question

All receptor tyrosine kinases have a single transmembrane domain.
a. true
b. false

Answer 1

It is true that all receptor tyrosine kinases have a single transmembrane domain, which is a key feature that aids in their role in cellular signal transduction.

Step-by-step explanation:

The question relates to the structural features of receptor tyrosine kinases (RTKs), which are crucial components involved in cellular response mechanisms. The assertion that all receptor tyrosine kinases have a single transmembrane domain is true. According to the referenced material, a receptor tyrosine kinase is described as an enzyme-linked receptor that has a single transmembrane region, along with extracellular and intracellular domains. The process initiated by these receptors includes ligand binding to the extracellular domain, receptor dimerization, autophosphorylation of tyrosine residues on the intracellular domain, and a subsequent downstream cellular response. This autophosphorylation step is crucial for propagating the signaling cascade, leading to various cellular outcomes. The signaling is terminated when a phosphatase enzyme removes the phosphate groups from the phosphorylated tyrosines.

Answer 2

This statement is True because,All receptor tyrosine kinases have a single transmembrane domain.

Explanation:

Receptor tyrosine kinases (RTKs) are integral membrane proteins that play a crucial role in signal transduction across the cell membrane. The majority of RTKs indeed possess a single transmembrane domain. This domain anchors the receptor in the cell membrane, allowing it to span the lipid bilayer. The single transmembrane domain is a common structural feature among RTKs and is essential for their proper functioning.

The transmembrane domain in RTKs serves a dual purpose. Firstly, it provides stability to the receptor by embedding it within the lipid bilayer, ensuring its proper orientation and localization. Secondly, it facilitates the transmission of signals across the cell membrane. The extracellular domain of the receptor interacts with ligands, leading to conformational changes that are transmitted through the transmembrane domain to the intracellular kinase domain. This activation triggers a cascade of intracellular events, ultimately influencing cell behavior.

Understanding the structural characteristics of RTKs, such as the presence of a single transmembrane domain, is crucial for unraveling their molecular mechanisms and designing targeted therapies. Researchers and pharmaceutical developers leverage this knowledge to create drugs that modulate RTK activity, contributing to advancements in the treatment of various diseases, including cancer and other disorders associated with aberrant RTK signaling.