[BIOL 100] - Midterm Exam Guide - Ultimate 18 pages long Study Guide!
Document Summary
Discuss the structure and function of the cell membrane. Discuss the structure and function of the cytoskeleton. Earliest organisms were prokaryotes- they lack the nucleus. Eukaryotes have cells with nucleus and membrane bound organelles. Cell membranes are composed of organic molecules called phospholipids (lipid + phosphate group) Each phospholipid has a hydrophilic head (polar) and two hydrophobic tails (non-polar) Phospholipids arrange themselves into a ball- micelle, many combine to form bilayer sheet -> turns into vesicle. Because of their chemical structure, phospholipids spontaneously form a bilayer in water. Phospholipid bilayer is semipermeable to lipids and small, non- polar molecules (tails block ions and polar molecules) Phospholipids and moveable proteins form a fluid mosaic: the cytoskeleton is a network of protein tracks and tubules serving several functions. Cell movement: microtubules from the internal framework of cilia and flagella (motile structures, adjacent microtubules slide against each other with the help of a specific protein, as a result, the cilium or flagellum bends.
