LSU Bio 1201 exam 2 Questions and Answers 100% Pass

LSU Bio 1201 exam 2 Questions and Answers 100% Pass why are membranes called phospholipid bilayers? phospholipids have hydrophilic head and hydrophobic tail, hydrophobic face inside of cell making 2 layers what is meant by fluid mosaic? Mosaic of proteins drifting laterally in fluid bilayer of phospholipids how are membranes adjusted for different temperatures? membrane fluidity adjusted by changing the ratio of unsaturated to saturated fatty acids how do the relative amounts of saturated and unsaturated fats change? if you are in a cold environment you want more saturated fats for your membranes to be fluid; warm environment you want more saturated fats to make your membranes more solid what is meant by membrane fluidity? not too solid, not too fluid why is fluidity an important property? preserves membrane function Henrique and Hanson performed experiments with pigs and examined the effects on the relative amounts of saturated and unsaturated fats. What did they find? found that membrane fluidity can acclimate to temperature; pigs raised wearing underwear in a hot room had subcutaneous fats with higher melting point what types of molecules can move easily across the membrane? small nonpolar molecules, gases, steroid hormones, and water what is simple diffusion? down the concentration gradient; does not require supplied energy; does not use a carrier molecule what is facilitated diffusion? down the concentration gradient; employs carrier molecule; does not require supplied energy what is active transport? work must me done; must use supplied energy; employs carrier molecule for which transport processes are carrier molecules involved? facilitated diffusion and active transport which transport processes require the input of additional energy? active transport what is a semi-permeable barrier? only some types of molecules pass through when equilibrium is reached in diffusion: does movement of molecules stop? no when equilibrium is reached in diffusion: does