Activity 19.2.2 – Properties of amino acids
Proteins are necessary for the structure and function of all forms of life. Some proteins serve as enzymes, facilitating biochemical reactions in the body, while others provide cellular structure, or serve specialized roles including immune response. Amino acids are the building blocks of all proteins. The sequence and frequency of amino acids in a protein influences its structure and function. Table 19.5 records some of the common properties of amino acids. This database file can be downloaded from the companion website, sciencesourcebook.com. Use the database commands to answer the following questions.
(1) Which amino acids are coded for by these codons? CCU, UAU, UCG, UUG. Perform a search (find) for each codon sequence.
(2) What is the rarest polar amino acid in vertebrates? Sort (arrange) in ascending polarity and look for the first polar amino acid in the list.
(3) What percent of proteins are composed of essential amino acids (those that cannot be synthesized by the human body, but must be acquired in food). Arrange (sort) by essential/non-essential. Perform a subtotal of the average percent composition at each change in the “essential” category.
(4) Which amino acids compose less than 7% of proteins in vertebrates, are neutral and polar? Perform three successive filters (less than 7%, neutral, polar). Make certain to show all records before performing subsequent operations or you will be working only with the results of the filter.
(5) Which amino acid has a molecular weight greater than 150 g/mole, is polar, and neutral? Perform three successive filters (mass greater than 150, polar, neutral). Make certain to show all records before performing subsequent operations.