(a) Where might bends occur?

3. The Ds transposable element of Zea mays cannot transpose on its own because it lacks _____.

第二部分：簡答題 1. How does one determine if two homolog proteins are paralogs or orthologs? 

(a) GGACRFPWDQPGTPN

(b) SEAENDEMARAALKA

(b) Where might intrachain disulfide cross-linkages be formed?

(c) Assuming that this sequence is part of a larger globular protein, indicate the probable location (the external surface or interior of the protein) of the following amino acid residues: Asp, Ile. Explain your reasoning.

4. At pH 7.0, in what order would the following three peptides be eluted from a column filled with a cation-exchange polymer? Their amino acid compositions are:     Protein A    : Ala 5%, Glu 10%, Gly 10%, Leu 5%, Asp 10%, Arg 5%, Met 5%, Cys 5%, Tyr 5%, Phe 5%, His 5%, Val 5%, Pro 5%, Thr 5%, Ser 5%, Asn 5%, and Gln 5%.     Protein B    : Ala 5%, Glu 5%, Ser 5%, Leu 10%, Arg 10%, His 5%, Ile 10%, Phe 5%, Tyr 5%, Lys 10%, Gly 15%, Pro 5%, and Trp 10%.     Protein C    : Ala 5%, Val 5%, Gly 10%, Asp 5%, Leu 5%, Arg 5%, Ile 5%, Phe 5%, Tyr 5%, Lys 5%, Trp 5%, Ser 5%, Thr 5%, Glu 5%, Asn 5%, Pro 10%, Met 5%, and Cys 5%.

5. Estimate the Vmax and Km of the enzyme-catalyzed reaction for which the following data were obtained. 

6. Describe the metabolic functions of the oxidative pentose phosphate pathway and the reductive pentose phosphate pathway. 

7. All of the intermediates in the glycolytic pathway are phosphorylated. Describe the reasons why this might be advantageous to the cell.