CAS BI 211 Lecture Notes - Lecture 2: Fluid Mosaic Model, Lipid Bilayer, Brownian Motion
Document Summary
Homeostatically regulated factors include: sensor, control center, effector. Bone (cid:862)sa(cid:448)i(cid:374)gs a(cid:272)(cid:272)ou(cid:374)t(cid:863) so hor(cid:373)o(cid:374)e that deposits (cid:272)al(cid:272)iu(cid:373) i(cid:374)to (cid:271)o(cid:374)e is a(cid:374) effe(cid:272)tor. Sensor control center (set point) effector. Plasma membrane review: made up of, phospholipid bilayer, proteins (transmembrane or peripheral, some carbohydrates, cholesterols, glycolipids, fluid mosaic model: reflects allowable movement of proteins within the phospholipid bilayer. Polarity review: polar: having 2 unequal sides, any molecule carrying charge or having an unequal distribution of electrons, ex. Water, ions, carbohydrates: polar = hydrophilic and lipophobic, non-polar = hydrophobic and lipophilic, think: water and lipids (fats) are opposites, (cid:862)like dissol(cid:448)es like(cid:863, polar head; nonpolar tail. Membranes restrict movement: membranes restrict molecular movement between compartments, molecules that are lipophilic/non-polar molecules can diffuse across the membrane, molecules that are polar/lipophobic cannot, most molecules in body are polar. Permeability: completely permeable to non-polar/lipophilic molecules, ex: oxygen, carbon dioxide, lipids, small non-polar molecules, selectively permeable to polar molecules, ex. Increased concentration gradient = faster rate of diffusion.
