BIO206H5 Lecture 19: BIO206 Lecture 19.pdf
Document Summary
Lipid composition changes frequently to adjust to a larger global scale. Massive proliferation of intracellular membrane increases surface area of cell. They are unique - amphipathic - both hydrophilic head and hydrophobic tail. Major groups you find are phospholipids, originating from (3 carbons) glycerol covalently linked by fatty acid tail via ester linkage - understand the structure! Pink (the head groups) - varies, these are modifications, make molecule more/ less electrically charged, form ionic interaction with other molecules) Sphingolipid - don"t really need to know the structure. Diffusion of highly charged molecules doesn"t occur easily. To minimize the physical tearing apart, the cell maximize fluidity. Fluidity depends on a # of physical factors (if cold, fluidity becomes rigid) Membranes need to be flexible because of environmental factors. The black molecule - carbon atoms, white - hydrogens. The molecules are fairly packed together - with heat, molecules become disordered and fluid-like which is more permeable.