Bio 101 Chapter 7: Membrane Structure and Functions Exam 2023.

Bio 101 Chapter 7: Membrane Structure and Functions Exam 2023. The permeability of a biological membrane to a specific polar solute may depend on which of the following? - Answer The types of transport proteins in the membrane. The lipid bilayer will be impermeable or very poorly permeable to polar or charged solutes. The presence of the correct transport protein will determine the permeability. Fluid Mosaic Model - Answer Membranes are fluid, membrane proteins and phospholipids can drift about in the membrane. The diverse proteins found in and attached to membranes perform many important functions. The framework of a membrane is a bilayer of phospholipids with their hydrophilic heads facing the aqueous environment inside and outside of the cell and their hydrophobic (unsaturated and saturated fatty acid) tails clustered in the center. Membrane Proteins - Answer Functions: transport, enzymatic activity, signal transduction, cell-cell recognition, intercellular joining, attachment In this diagram of the plasma membranes of two adjoining cells, identify the protein indicated by the white arrow, including its function - Answer a receptor protein that binds with a signaling molecule and relays the message into the cell by activating other molecules inside the cell. Signaling proteins are part of signal transduction pathways that transmit external chemical signals into the cell. You are working on a team that is designing a new drug. For this drug to work, it must enter the cytoplasm of specific target cells. Which of the following would be a factor that determines whether the molecule selectively enters the target cells? - Answer The similarity of the drug molecule to other molecules that are transported into the target cells. If the target cells have transport proteins that specifically bind to certain molecules, they may bind with and transport a drug that is similar in structure