Cell Signaling 101

• Ligands deliver signals for normal cell growth.
• Ligands can be growth factors, inhibitors, extracellular matrix components, or cell adhesion molecules.
• Receptors on cell surfaces transmit signals into the cell.
• Receptors often consist of three domains: extracellular ligand-binding, transmembrane, and intracellular.
• Tyrosine kinase is a receptor activated by ligand binding.
• Tyrosine kinase activates other proteins by phosphorylation.
• Normal cells respond to ligand binding by activating a cascade of signals.
• The nucleus is signaled to promote cell growth and division or stop growth.
• Cellular restraints on gene expression limit receptor production.
• Protein translation is also a factor in receptor production.

Test your knowledge on ligands and receptors with this quiz! Learn about the different types of ligands and how they signal for cell growth, as well as the structure and function of receptors on cell surfaces. Find out how tyrosine kinase is activated and what happens when normal cells respond to ligand binding. Explore the limitations on receptor production and protein translation in this informative quiz. Keywords: ligands, receptors, cell growth, tyrosine kinase, phosphorylation, gene expression.