KAAP309 Lecture Notes - Lecture 2: Cytosol, Microtubule, Chromatin

• School: University of Delaware
• Department: Kinesiology & Appl Physiology
• Course: KAAP309
• Professor: Rose William

Document Summary

Plasma membrane structure: lipid bilayer with proteins in a constantly changing fluid mosaic, dynamic role in cellular activity, separates intracellular fluid from extracellular fluid. Interstitial fluid= ecf that surrounds cells: membrane proteins. Firmly inserted into the membrane (most are transmembrane) Transport proteins (channels and carriers), enzymes or receptors. Include filaments on intracellular surface and glycoproteins on extracellular surface. Functions: enzymes, motor proteins, cell-to-cell links, provide support on intracellular surface, and form part of glycocalyx. Tight junctions: impermeable junctions prevent molecules from passing through the intracellular space. Desmosome: anchoring junctions bind adjacent cells together and help form and integral tension-reducing network of fibers. Gap junctions: communicating junctions allow ions and small molecules to pass from one cell to the next for intracellular communication. Substances move down its concentration gradient: simple (lipid-soluble molecules) Substances diffuse directly through the phospholipid bilayer: facilitated: certain lipophobic molecules use carrier proteins or channel proteins. Are saturable: rate is determined by number of carriers or channels.