Problems
4.1 Does the change from a solid to a liquid represent a phase change?
4.2 Does the expansion of a metal during heating represent a phase change?
4.3 Why does adding salt to a mixture of ice and liquid water cause the temperature to drop?
4.4 What is the general structure of a phospholipid?
4.5 Explain how chemical potentials predict the behavior of detergents and lipids and how the
second viral coefficient is used.
4.6 Explain the difference between a liposome and a micelle.
4.7 What is the critical micelle concentration?
4.8 How would a phase diagram be expected to change if the hydrocarbon chain of a detergent
became longer?
4.9 Some lipids can form complex structures in what is termed a cubic lipid phase. Estimate
where this phase would be found relative to other phases on a phase diagram for this lipid.
4.10 What is a lipid raft?
4.11 Why are these results from cell-fractionation experiments not definitive indicators for the
presence of lipid rafts?
4.12 Why is the concentration of glycosylphosphatidylinositol (GPI)-anchored proteins thought
to be important to the function of lipid rafts?
4.13 How high does water travel up a capillary with a radius of 2.0 mm?
4.14 If a blue liquid travels up a capillary only half as high as red liquid, what can be concluded
about the two liquids?
4.15 Why does the surface tension of a detergent solution stop decreasing once the detergent
concentration reaches a certain value?
4.16 What can be said about the enthalpy change associated with the mixing of two different
ideal gases at constant temperature?
92 PARTI THERMODYNAMICS AND KINETICS
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