~plasma membrane made up of phospholipids, hydrophobic middle layer with hydrophilic heads. ~trans/integral membrane proteins go right through the membrane. ~peripheral protein mostly on cytoplasmic side of membrane, have lipid o(cid:374) top that"s tryi(cid:374)g to get i(cid:374)to middle of membrane. ~carbohydrate chains are very important for giving signals to proteins. ~microfilaments attach to proteins on membrane and create a matrix. ~membrane stays as a liquid and must maintain that fluidity. Wo(cid:374)"t (cid:271)e solid the(cid:374) a(cid:374)d too (cid:373)a(cid:374)y or (cid:374)o (cid:373)ole(cid:272)ules will go through. ~desaturase, long carbon chains that prevent kinking of the tail by creating a double bond. Cholesterol can prevent phospholipids from packing too tightly, prevents it from becoming solid. Small channels allow tiny molecules to go through without assistance along concentration gradiant (facilitated transport) Or use atp to move specific molecules through a channel, (active transport: enzymatic activity. Group all enzymes for a common pathway: signal transduction. Can change shape of protein, causing chemical reactions w/ cell: attachment/recognition.