MCB 2210 Lecture Notes - Lecture 8: Threonine, Phosphatase, Phosphodiesterase
Document Summary
Do the problem sets, the answers are online. The cell membrane is a barrier to many kinds of information. Hydrophobic signaling molecules can cross the membrane directly (without the help of proteins: steroid hormones: receptor located in the cytoplasm or on nuclear membrane. Often affect gene expression: nitric oxide/ carbon monoxide: dissolved gas regulates many pathways. Hydrophilic signaling molecules cannot cross the membrane: they need to indirectly signal across the membrane by binding to the extracellular domain of transmembrane receptor proteins. Transmembrane receptor proteins go through the membrane. The external part binds to the signaling molecule and the internal part initiates a signal pathway within the cell. Types of signals: signaling via second messengers: Autocrine: releases signals that act upon itself. Endocrine: long-range signaling (different parts of the body: contact-dependent signaling: Cell surface receptor binds a signal on the surface of another cell or to extracellular matrix.