Name and draw the structures of the amino acids that fit the following descriptions:
a. Contains an isopropyl group

Verified step by step guidance

1. Step 1: Recall that amino acids are organic compounds containing both an amino group (-NH₂) and a carboxyl group (-COOH), along with a unique side chain (R group) that determines their identity.
2. Step 2: Identify the amino acid that contains an isopropyl group in its side chain. An isopropyl group is a branched alkyl group with the structure -CH(CH₃)₂.
3. Step 3: The amino acid with an isopropyl group in its side chain is **valine**. Its side chain is -CH(CH₃)₂, making it a nonpolar, hydrophobic amino acid.
4. Step 4: Draw the structure of valine. The general structure of an amino acid is: H₂N-CH(R)-COOH, where R is the side chain. For valine, R = -CH(CH₃)₂. The full structure is: H₂N-CH(-CH(CH₃)₂)-COOH.
5. Step 5: Label the functional groups in the structure. Highlight the amino group (-NH₂), the carboxyl group (-COOH), and the isopropyl side chain (-CH(CH₃)₂) to ensure clarity in the representation of valine.

Key Concepts

Amino Acid Structure

Amino acids are organic compounds that serve as the building blocks of proteins. Each amino acid has a central carbon atom (the alpha carbon) bonded to an amino group (-NH2), a carboxyl group (-COOH), a hydrogen atom, and a variable side chain (R group) that determines the specific properties of the amino acid. Understanding the general structure of amino acids is essential for identifying specific ones based on their side chains.

Isopropyl Group

The isopropyl group is a branched alkyl group derived from propane, consisting of three carbon atoms with the structure -CH(CH3)2. In the context of amino acids, the presence of an isopropyl group in the side chain indicates that the amino acid has a hydrophobic character, influencing its interactions and positioning within proteins. Recognizing this group is crucial for identifying the correct amino acid.

Hydrophobic Interactions

Hydrophobic interactions refer to the tendency of nonpolar substances to aggregate in aqueous solutions to minimize their exposure to water. Amino acids with hydrophobic side chains, such as those containing isopropyl groups, play a significant role in protein folding and stability. Understanding these interactions helps in predicting how amino acids will behave in a protein's three-dimensional structure.