BIOL 2160 Chapter : Chapter 4
Document Summary
Chapter 4: cell membrane transport: membrane mostly phospholipid and proteins and % of each varies with structure; protein=lipid, rbcs= 50:50, myelin sheath= 20:80. Inner mitochondrial membranes= 76:24 (these numbers are not to be memorized: phospholipids: polar head and 2 non-polar tails, micelles: droplets of fat with a phosphate on in the inside and a fatty acid on the outside. Ions do not move freely across: movement across membranes, membrane= barrier between ecf and icf, selective permeability, non-polar and small polar cross, o2, co2, fatty acids, water. Lipid soluble molecules (steroids: small polar covalent bonds (co2, h2o (small size, lack charge, the larger the molecules, the more slowly it will diffuse, cell membrane impermeable to: 4. 14)****: both ions move up their electrochemjcal gradients, model of active transport. 4. 15a: occurs in adipose cells, a way to get glucose into the cell, figure 4. 15- countertransport (the opposite of co- transport, sodium will always move into the cell down electrochemical gradient, symport= co-transport.
