BIO 3124 Lecture Notes - Lecture 5: Facilitated Diffusion, Lipid Bilayer, Uniporter
Document Summary
Bacteria are very small (1-4um) which allows for a high ratio of surface area relative to volume. This favours diffusion and absorption (exchange) allowing for quick nutrient uptake and waste elimination. This small size also allows for rapid growth, and high cell density: plasma membrane. Phospholipids are composed of the hydrophilic polar head and fatty acid hydrophobic tail core (amphipathic molecules) Bacteria try to maintain hypertonic states (relative to outside: passive passage. Passive passage is a mechanism that moves molecules through the membrane without an investment of energy (free). The speed at which passage occurs as a function of concentration. The greater the concentration, the faster it goes. The greater the difference i concentration, the faster it goes. Much less dependent on concentration (speed is not so much a function of concentration, more a function of how fast a transporter can go) Plateau: max speed at which a transporter can work (vs. passive diffusion) = vmax.
