Chemistry Sample Assignment

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Answer:
Part 1:

The deoxygenated form of hemoglobin is stabilized by the following interactions:

1. Asp 94 via its carboxylate side chain forms a salt bridge with the charged imidazole group of His 146 which is the carboxy terminal amino acid in the beta-chain.

2. The carboxyl carbon of Val 98 forms a hydrogen bond with the tyrosine hydroxyl group at position 145. The effect of these first two interactions is to position helices F and H in close proximity.
3. The free carboxylate group of His 146 forms a salt bridge with amino group of the side chain of Lys 40 of the alpha chain. It allows communication between 2 subunits and keeps the beta chain H helix close to the alpha subunit.

Part 2:

The characteristic and physical properties of valine are listed as follows:

1. It is non polar branched amino acid.
2. In sickle cell anemia, valine is replaces glutamic acid in hemoglobin therefore it is not able to fold properly.
3. It is coded by GUU, GUC, GUA and GUG.
4. It is synthesized in several steps starting from pyruvic acid.
5. It is an essential proteinogenic amino acid.

A peptide or amide bond (C(O)NH) is a covalent chemical bond formed when the carboxyl group of one molecule reacts with the amino group of the other molecule, causing the release water molecule. This process is also called dehydration synthesis and the resulting bond is called a peptide bond and the resulting molecule is called amide. Carboxyl group amino group peptide bond water