Question

Cell surface receptors. Diagram the reception, transduction, & response for hormones that act on cell surface receptors. What does the G Protein-coupled receptor cladogram say?

What do second messengers do?

Signaling cascades. How does this amplify a signal?

How can different types of cells respond differently to the same hormone?

Steroid hormones: Diagram the reception, transduction, & response. Why are the mechanisms different for steroid hormones vs. protein hormones? Are the signals amplified?

Answer 1

Cell surface receptors are the specialized intra membrane proteins that allows the communication between the extracellular molecules(hormones. neurotransmitter, cytokines , growth factors etc.) and the inside of the cells.

There are mainly three types of cell surface receptors-

• Ion linked receptors
• Enzyme linked receptors
• G-protein coupled receptors

G-protein coupled receptors, which is one of the most common cell surface receptors in eukaryotes, activates the heterotetrimeric G-protein subunits,which are potential activators of Phospholipid signalling enzymes(PIPKs). In oomycetes and slime moulds, the phospholipid active enzymes are an accesory domain of the GPCR, which causes their direct activation. these is revaled by cladograms.

Second messengers relay the signals, recieved by the surface receptors to the target molecules , inside the cell.

Signal cascade- these are the set of chemical reactions that happens when there is the activation of receptors and is carried out until the signal is carried to the target molecule.

In different types of cells there is different cascade mechanisms, and there is different results to the signals recieved by the surface receptors.Thats why different cells can react differently to the same hormone.

Steroid hormones-these are the intracellular hormones that reacts to the steroid hormones. It is present in the cytosol, nucleus and plasma membrane of the target cells.

It follows two mechanisms-\

• genomic-which are again divided into type I and type II
• Non genomic- The aldosterone receptors in the cell membrane, which is shown to inrease the activity of basolateral Na/K+ ATPase pump.