BIO 1140 Lecture Notes - Lecture 4: Tight Junction, Membrane Fluidity, Glycosphingolipid

• School: University of Ottawa
• Department: Biology
• Course: BIO 1140
• Professor: Caroline Petit- Turcotte

Document Summary

Question to reflect on: this is an axon; propose a way this portion of a cell can grow to reach a target (muscle, neuron, etc). Describe the structural elements involved and the steps required. Part of the cell, different type of layer just like a plasma membrane in animal cells. Cell to cell interactions: tight junctions: fusion of proteins on plasma membranes. Extracellular matrix is practically irrelevant or not existent because of the airtight seal provided by tight junctions: anchoring junctions: plaques anchors cells together. (adherens - actin and cadherins) (desmosomes - if, keratins) (mechanical force) Intermediate filaments which come together to form a junction between cells: gap junctions: channels formed by proteins bridging cells (connexins (proteins shaped like a ring). Allows passage of ions and small molecules - cell communication. Sensory proteins that can detect ions particularly calcium - when the ions are low the gap junctions open allowing the ions to flow through.