Signal transduction is the passing of signals within a cell.

These signals are passed through "paths" of predominantly proteins. For example, a protein may be "switched" by attaching a phosphate group to a certain position (phosphorylation by a kinase). In this way, a signal can be led by the cell to the place where it is needed, after which something can happen to the cell, for example, move, die (or not), start sharing, etc.

In addition to the signals within the cell, there are also signals from outside the cell with special signal substances, such as hormones, neurotransmitters and other molecules. Examples Signal Amplification

The most successful form of signal amplification is through the formation of secondary messenger molecules, which typically activate protein kinases. Examples of these are: adenylate cyclase (AC), phospholipase C (PLC), tyrosine-specific protein kinases (TPK; N.B .: T stands for tyrosine, and the usual single-letter code Y is not used!).

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