Q. 16.62 - An Introduction to General, Organic, and Biological Chemistry

Question

a. Draw the condensed structural formula for Val-Ala-Leu. 

b. Would you expect to find this segment at the center or at the surface of a protein? Why?

Step-by-Step Solution

Answer

Part a)

                 

Part b)    

• The R groups on the amino acids of this peptide are non-polar.
• This section was discovered in the middle of the protein  structure.

step-1 Given information (part a)

• Amino acids have two functional groups: an amine$\left(-{\mathrm{NH}}_2\right)$ and a carboxylic acid $(-\mathrm{COOH})$.
• The a-carbon is covalently linked to both functional groups. 
• All proteins are constructed from amino acids. A dipeptide is formed when two amino acids are linked by an amide bond formed between the amine group of one aminoacid and the carboxylic group of the second aminoacid.
•  Proteins are macromolecules made up of amino acids, which are repeated building blocks that affect the form and function of the protein.

step-2 Explanation (part-a)

                            

  

step-3 Given information (part-b)

• The aliphatic side chains of hydrophobic amino acids make them water insoluble. 
• These hydrophobic amino acids are present inside the protein structure, whereas hydrophilic amino acids have polar side chains and can be found on the surface or outside.

step-4 Explanation (part-b)

•  This peptide has non-polar R groups on amino acids. As a result, this section was discovered in the middle of the protein  structure.