Instructions: Refer to the data below to answer the following ...

[natalie2426]

Instructions: Refer to the data below to answer the following question(s).
 
   Porcine dynorphin is a neuropeptide having 17 amino acid residues. Its structure is shown below.
 
   TyrGlyGlyPheLeuArgA rgIleArgProLysLeuLy sTrpAspAsnGln

  Refer to instructions. What fragments would result if dynorphin were cleaved by trypsin?

Question 2

Draw the structure of the product of the following reaction and describe the usefulness of this type of reaction.
 
   

Question 3

Write the equation for the reaction, using methanol (CH₃OH), that would render the carboxyl group of alanine unreactive.

Question 4

Draw and name the structure of the product of the following reaction.
 
   

Question 5

Instructions: Consider the following structure. Based on this structure answer the following question(s).
 
   

  Refer to instructions. How many other peptides could be formed from this same combination of amino acids?
   
  a.
  3
   
  b.
  6
   
  c.
  9
   
  d.
  12

Question 6

Instructions: Consider the following structure. Based on this structure answer the following question(s).
 
   

  Refer to instructions. Name the peptide using both the three-letter and one-letter codes.

Question 7

Instructions: Consider the following structure. Based on this structure answer the following question(s).
 
   

  Refer to instructions. Circle the peptide bonds.

Question 8

Instructions: Consider the following structure. Based on this structure answer the following question(s).
 
   

  Refer to instructions. Identify the C-terminal amino acid and the N-terminal amino acid.

Question 9

Instructions: Refer to the data below to answer the following question(s).
 
   Leucine is an essential amino acid with the systematic name 2-amino-3-methylpentanoic acid. It has pK_a1 = 2.36 and pK_a2 = 9.60.

  Refer to instructions. Leucine is described as an essential amino acid. What does this mean?

[johnharpe]

Answer to Question 1

Trypsin catalyzes the hydrolysis of peptides as the carboxyl side of arginine and lysine. Consequently, the fragments resulting from trypsin hydrolysis of dynorphin are:

TyrGlyGlyPheLeuArg

Arg

IleArg

ProLys

LeuLys

TrpAspAsnGln

Answer to Question 2


Removal of a protecting group that was added to the carboxyl group. Often used in protein synthesis

Answer to Question 3



Answer to Question 4



Answer to Question 5

b

Answer to Question 6

SerPheGly

SFG

Answer to Question 7



Answer to Question 8



Answer to Question 9

Humans are able to synthesize only 10 of the 20 amino acids necessary for protein synthesis. The remaining 10 are called essential amino acids since they must be obtained from dietary sources. Failure to include an adequate dietary supply of these essential amino acids can lead to severe deficiency diseases.