How does the structural organization of membranes provide for transport and recognition?

Membranes are held together by hydrophobic interactions

Proteins and lipids can move around laterally on one layer but rarely flip to the other side

Some move along the cytoskeleton fibers

Membrane remains fluid as temperature decreases until the phospholipids settle into a closely packed arrangement

Membrane remains fluid longer if there are more phospholipids with unsaturated hydrocarbon tails

Separated more because of the kinks in the tails

Cholesterol

At higher temperatures, it makes the membrane less fluid

Restrains phospholipid movement

Lowers the temperature required for membranes to solidify because they are packed less tightly

Temperature buffer

stimulus is a change in the environment that causes an organism to react. the response is the reaction to the stimulus. some examples of stimuli for zebras are drought, to many predators, and bad feeding grounds such as dead grass or plants. zebras respond to stimuli just like all other living organisms

layer 3 is younger than layer 6.