Select all amino acids that match the description. the r groups of this class of amino acids are non-polar and hydrophobic, and their side chains tend to cluster together within proteins, stabilizing protein structure by means of hydrophobic interactions:
a) leucine. b) isoleucine. c) alanine.

A) Leucine.

B) Isoleucine.

C) Alanine.

Explanation:

Alanine has a "CH3" group as its R group which in turn is a non-polar functional group making it a non-polar amino acid. Similarly, leucine has a branched hydrocarbon as its side chain. So, leucine is also a non-polar amino acid. A branched hydrocarbon chain with four carbon atoms makes the R group of isoleucine.

This makes all of these three amino acids non-polar. The non-polar amino acids are present away from the surrounding water and mostly make the cores of the proteins where their non-polar side chains cluster together. These amino acids form several hydrophobic interactions to make the proteins stable.

the cytokine-activated janus kinase (jak)-signal transducer and activator of transcription (stat) pathway has an important role in the control of immune responses. dysregulation of jak-stat signaling is associated with various immune disorders.