Physiology 1021 Chapter Notes - Chapter 3: Sodium Chloride, Facilitated Diffusion, Resting Potential

• School: Western University
• Department: Physiology
• Course: Physiology 1021
• Professor: Tom Stavraky

Document Summary

Made up of proteins that form channels and pores, carbohydrate molecules for cell recognition, and cholesterol for stability. Most abundant components of the cell membrane are the phospholipid molecules. Diffusion of lipid-soluble substances substances that are fat soluble can pass right through the cell membrane, while those that are water soluble have a tougher time fat-soluble substances: oxygen, carbon dioxide, fatty acids, some steroid hormones. Therefore, a positive ion will not go through a channel that has a positive charge: the greater the electrochemical gradient of a molecule, the greater its rate of movement through the channels. Substances move down both their [ ] and electrical gradients (recall the opposite charges attract: the number of channels in the membrane affects the rate. [ ] gradient for an ion, that ion will not move across the membrane unless there are channels for it. The more channels that exist, the move ions that will diffuse across the membrane.