请回答下列问题(每题10分)。

1. 水在不同温度所具有的结构？为何水的结构对蛋白质二级结构及蛋白质-蛋白质间的交互作用中具有重要性？水合作用对维持蛋白质的溶解度具有重要性。如何达到的呢？

2. 请绘出20个左旋氨基酸与4个核苷酸的结构。请写下它们的全名、三字码与单字码。请依据氨基酸支链的性质来分类：疏水性、亲水性、极性与非极性。请简短解释每一“类”与水的交互作用的倾向。请绘出带电氢键的形成，并解释它们如何与水作用。请绘出核苷酸碱基的所有可能氢键。

3. 请描述下列二级结构的基本特性。并解释它们在决定蛋白质与蛋白质材料结构上的功能。

a. α-螺旋
b. 310螺旋
c. p螺旋
d. β螺旋
e. β折叠
f. 转角与回环
g. 胶原螺旋

4. 请详细描述肽键的形成与其结构。你可以基于肽键结构推导出其它结构吗？

5. 卷曲螺旋有何特性？请描述二股、三股与四股的卷曲螺旋。在自然界中何处可以发现这样的卷曲螺旋？

6. 请解释胶原蛋白的高解析度晶体结构的重要性。我们从晶体结构中可以学到什么？请解释为何氨基乙酸与脯氨酸对胶原蛋白结构的形成是很重要的？胶原蛋白如何进行自组装？

7. 请描述蚕丝与蜘蛛丝的分子结构。这二种蛋白质均含有大量的甘氨酸。这些甘氨酸残基是如何在丝状结构中排列？

8. 请简短地解释用于确定生物材料的分子结构的X射线晶体学的工具。请简短地解释用于确定生物材料分子结构的核磁共振工具。

9. 请描述自然界如何制造不同类型的生物矿物。

10. 利用你在课堂上所学到的知识来设计一个有趣的结构主题(提示：利用不同的重复序列)。

X. 另外的选择：你可以利用下面的方式来取代上面(1-9)中的一个问题：

询问一个我们在课堂上所包括的相关材料中你所认为是一个重点的问题。然后简短地回答你的问题。

Please answer each of the questions (10 points each).

1. What is the structure of water at different temperatures? Why is the structure of water important in the formation of protein secondary structures and protein-protein interactions? Hydration is important for maintaining a protein soluble. How?

2. Please draw the structures of 20 L-amino acids and 4 nucleotides. Write their full names, three-letter code and one letter code. Please group amino acids according to the nature of their side chains: hydrophobic, hydrophilic, polar and nonpolar. Explain briefly each group’s tendency to interact with water. Please draw the potential hydrogen bond formations and explain how they interact with water. Draw all possible hydrogen bonds for the nucleic acid bases.

3. Describe the basic characteristic of the following secondary structures. Also, explain their function in determining the structures of protein and protein-materials.

a. alpha-helix
b. 310 helix
c. p helix
d. beta-helix
e. beta-sheet
f. turns and loops
g. collagen helix

4. Describe peptide bond formation and its structure in great detail. Can you deduce other structure formations based on the peptide bond structure?

5. What is characteristic of coiled-coils? Describe two, three and four strands of coiled coils. Where do you find such coiled coils in nature?

6. Explain the significance of the high-resolution crystal structure of collagen. What have we learned from the crystal structure? Explain why glycines and prolines are important in forming structure of collagen? How do collagens undergo self-assembly?

7. Describe the molecular structures of silkworm silk and the spider silk. Both proteins have high content of glycine. How are these glycine residues arranged in the silk structures?

8. Briefly explain the tool of X-ray crystallography used in determination of the molecular structure of biological materials. Briefly explain the tool of NMR in determination of the molecular structure of biological materials.

9. Describe how nature makes various types of biominerals.

10. Using the knowledge you have learned in the class to design an interesting building structural motif (hint: use various repeating sequences).

X. Alternative: You may replace a question above (1-9) with the following:

Ask a question related to the material we have covered in class that you think probes an important point. Then answer your question briefly.