Unit 2 Progress Check Frq 9 Correctly Answered Questions Latest Update

(a) Identify the most likely mode of transport across the membrane for substance L. Explain how information provided helps determine the most likely mode of transport. {Ans: The most likely mode of transport across the membrane for substance L is active transport. Active transport moves substances against the concentration gradient from an area of lower concentration to an area of higher concentration. Even though the cell has a higher concentration of substance L, L still enters the membrane by active transport which consumes energy rather than releasing it.}(c) Determine the external concentration of substance L that will result in one-half of the maximal entry rate. {Ans: 33mM}(a) Describe the biological need for cells to be surrounded by a membrane that is selectively permeable for different materials. {Ans: Having a semi-permeable membrane allows cells to control the passage of material coming in and going out. It allows cells to maintain a homeostatic condition by only allowing certain molecules to cross the cell, which is necessary for cell functioning and survival.}(c) Describe the characteristics of the phospholipid bilayer that permit small hydrophobic lipid molecules to pass directly across the membrane. {Ans: The phospholipid bilayer's phospholipid molecules each have