Biology 1107 exam 2 questions and answers all are graded A+

Which of the following factors influence the rate at which molecules can diffuse? A. Temperature B. Pressure differential C. Mass of molecule D. Gradient size - Answer-ABCD A red blood cells is placed in a solution that has a higher concentration of impermeable solutes than inside of the cell. What is the result? A. Cell will increase in size B. Cell will decrease in size C. Cell will swell and burst D. Nothing - Answer-B. Water flows from low to high concentration What prevents concentrations from completely equalizing - Answer-Gravity Substances move from an area of _____ concentration to an area of ______ concentration - Answer-high to low Heavier molecules diffuse - Answer-Slower as temp increases, diffusion - Answer-Increases As density of solvent increases, rate of diffusion - Answer-Decreases How would the fluidity and permeability of cell membranes in animals change if the amount of cholesterol in those cell membranes increased? A. Increase B. DecreaseC. No chance - Answer-B because cholesterol increases membrane packing, making it more rigid Which of the following will increase the fluidity and permeability of cell membranes in animals A. Reducing lengths of fatty acids in phospholipids B. Reducing cholesterol amount in membranes C. Reducing fatty acid saturation in phospholipids D. Adding double bonds to phospholipid fatty acids - Answer-ABCD Channel protein - Answer-Form openings in cell membrane to allow passive diffusion of substances— facilitated diffusion, no energy Carrier proteins - Answer-Reversibly change their shapes to enable the passive diffusion of certain substances (facilitated diffusion) Pumps - Answer-Reversibly change shape to ACTIVELY transport substances, usually against concentration gradient (low to high) sodium-potassium pump - Answer-a carrier protein that uses ATP to actively transport sodium ions out of a cell and potassium ions into the cell Bulk transport - Answer-Used to engulf of expel substances Active Co2 is more concentrated inside the cells than outside of the cells. What type of transport will be used to move CO2 out of cells? A. Active B. Facilitated diffusion C. Transport not likely D. Simple diffusion - Answer-D. Going with gradient (high to low)