Think about the Arctic flounder that lives in cold Arctic waters and the Arabian camel that lives in hot deserts. How might these Arctic flounder and Arabian camel modify the lipid composition of their cellular membranes to withstand their respective environments? Also, how would these modifications relate to the transition temperature of the lipid bilayer? And how could such adaptations affect the function of proteins within the membrane and the overall performance of the cell?

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Mark the following statements about the plasma membrane as true or false. If a statement is false, correct it to make a true statement. a. _____ Integral membrane proteins generally span the width of the plasma membrane, whereas peripheral proteins are found on only one side of the membrane. b. _____ Cholesterol provides the plasma membrane with stability in the face of changing ion concentrations . c. _____ Membrane cholesterol is vitally important for cell-cell recognition. d. _____ Membrane proteins often function as channels or carriers. e. _____ The overall structure of the plasma membrane is a mosaic with the components locked tightly in place

Answer the following question in few paragraphs: The actual network and the microtubule network within a cell display very similar assembly kinetics yet has drastically different mechanisms that regulate the dynamics of the individual networks. Compare and contrast the dynamics, both assembly and disassembly, of Actin and microtubules. Be sure to elaborate why these distinctions exist.

In conditions of dehydration, plant cells can increase their water retention by regulating the function of some or all of their aquaporins, membrane-bound protein channels that allow water to move through the cell membrane via facilitated diffusion. Which of the following describes a likely mechanism by which aquaporins can be used to regulate the movement of water across the plant cell membrane? A B с D Synthesis of additional aquaporins by the plant cell ribosomes will allow the cell to coun- teract the movement of water out of the cell. Inhibition of ATP hydrolysis will make the aquaporins unable to remove water from the cell and cause more water to remain in the cell. Inactivation of aquaporins will make water molecules unable to move across the plant cell membrane and allow more water to remain in the cell. Inhibition of the plant cell Golgi apparatus will decrease the production rate of vesicles and slow down the exocytosis of water molecules.