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There are four basic categories of chemical signaling found in multicellular organisms: paracrine signaling, autocrine signaling, endocrine signaling, and signaling by direct contact.

How single-celled organisms use signals to communicate. Yeast mating types, bacterial quorum sensing, and biofilms.

Learn how signals are relayed inside a cell starting from the cell membrane receptor. The chains of molecules that relay intracellular signals are known as intracellular signal transduction …

Direct contact involves gap junctions or complementary surface proteins. Paracrine communication happens over short distances, while endocrine signaling involves hormones …

In general, however, mutations of two types of cell cycle regulators may promote the development of cancer: positive regulators may be overactivated (become oncogenic), while negative …

This process starts when molecules outside the cell interact with cell receptors, setting off a chain of events. G-proteins, acting like molecular switches, play a key role here.

Plants and fungi have a tough cell wall for protection and support, while animal cells can secrete materials into their surroundings to form a meshwork of macromolecules called the …

Types of signaling molecules and the receptors they bind to on target cells. Intracellular receptors, ligand-gated ion channels, G protein-coupled receptors, and receptor tyrosine kinases.

Prepare to dive deep into the inner workings of cells! In this unit, you'll learn about how cells communicate with one another, how cells divide, and how problems can arise when these …