Set Problem 1 for BIBC 100
Winter 2005
1. Certain insects can "skate" along the top surface of water in ponds. What property of water allows them to do this and what bonds or interactions are involved? 2. Compound Glycine Glutamate Arginine
pK1 2.34 2.19 2.17
pK2 9.60 9.67 9.04
pKR 4.25 12.48
pI 5.97 3.22 10.76
a) What do the pK values tell you? b) Will the following amino acids have an overall positive, negative or zero charge at pH 3.22, pH 5.97, pH 10.76? Fill in the chart. pH 3.22 Gycine Glutamate pH Arginine 5.97 pH 10.76
3. Calculate the net charge on the following tripeptides at pH7. a) Asp-Glu-Ser b) Ser- Gly-Thr c) GlyLys-Arg 4. Refer to Table 3-2 in the textbook for this question: a) How many proteins in the table exhibit quarternary structure? How can you tell? b) How many proteins exhibit supersecondary structures? How can you tell?
5. How would the following agents/procedures interfere with/disrupt the different levels of protein architecture? Why? a) addition of SDS b) addition of protease