what are three main parts of human body cell? a. plasma membrane, organelles, cytoplasm b. plasma membrane, organelles, nucleus c. plasma membrane, cytoplasm, organelles d. plasma membrane, cytoplasm, nucleus e. plasma membrane, cytosol, organelles - ANS-d. plasma membrane, cytoplasm, nucleus briefly describe the fluid mosaic model - ANS-the fluid mosaic model states that the molecular arrangement of the plasma membrane resembles an ever-moving sea of fluid lipids containing a mosaic of many different proteins the three main components of lipid bilayer portion of plasma membrane are a. phospholipids, glycoproteins, & water b. proteins, cholesterol, & fatty acids c. cholesterol, triglycerides, & glycolipids d. phospholipids, cholesterol, & glycolipids e. phospholipids, cholesterol, & proteins. - ANS-d. phospholipids, cholesterol, & glycolipids what are nonpolar parts of phospholipids? a. phosphate-containing head groups b. fatty acid tail groups c. both head & tail groups are nonpolar d. neither head nor tail groups are nonpolar - ANS-b. fatty acid tail groups polar portion of cholesterol molecule, which forms hydrogen bonds w/ polar heads of neighboring phospholipids & glycolipids, consists of a. -OH group b. -CH3 group c. -CH4 group d. -COOH group e. none of these choices correct - ANS-a. -OH group which type of membrane protein extends across entire lipid bilayer of plasma membrane touching both intracellular fluid & extracellular fluid? a. complement protein b. transmembrane protein c. peripheral protein d. lipoprotein e. all choices are correct - ANS-b. transmembrane protein describe five different functions of integral membrane proteins. - ANS-some membrane proteins act as ion channels or carriers that transport substances across membrane. other membrane proteins act as receptors that allow cell to respond to various types of ligands. other membrane proteins are enzymes that catalyze specific chemical reactions. still other membrane proteins act as linker proteins that anchor cells to neighboring structures including other cells. lastly, some membrane proteins serve as cell identity molecules. this type of membrane protein enables cells to catalyze specific chemical reactions at inner or outer surface of their plasma membrane a. receptors b. phospholipids c. cholesterol d. enzymes e. ligands - ANS-d. enzymes which of following types of membrane proteins function by recognizing & binding to hormones & neurotransmitters? a. transporters b. receptors c. enzymes d. linkers e. cell identification markers - ANS-b. receptors which type of membrane protein anchors cells to neighboring cells & to protein filaments found outside or inside cell? a. transporters b. receptors c. ligands d. ion channels e. linkers - ANS-e. linkers plasma membranes are ___________, which means that some chemicals move easily through plasma membrane while other chemicals do not. a. selectively permeable b. concentration graded c. electrically graded d. selectively soluble e. electrical insulators - ANS-a. selectively permeable which of following does NOT influence rate of diffusion of chemical across plasma membrane? a. concentration gradient of chemical across membrane b. mass of diffusing chemical c. distance that chemical has to diffuse d. amount of ATP available e. temperature - ANS-d. amount of ATP available briefly describe driving force for movement of water across plasma membranes - ANS-water moves across membranes by osmosis, which is driven by solute concentration differences across the membrane. water moves from area of low solute concentration to area of high solute concentrations