Which of the following amino acids is most likely to be found in a transmembrane alpha-helix?
a. histidine.
b. leucine.
c. lysine.
d. glutamine.

 The correct assertive is letter B, Leucine.

Explanation:

 Amino acids are important compounds for body maintenance and energy building. The set of several amino acids is called protein. In the case of a transmembrane protein, it is the set of several amino acids that surrounds the entire biological membrane to which it is permanently attached.

 In the case of transmenbranar proteins, there are two types: single-step transmembrane and multi-step transmembrane. It is in a single-step transmembrane subtype that we have the alpha helix and the amino acid leucine, which is the transmembrane domain subtype.

regulation of gene expression. gene expression can be regulated by various cellular processes with the aim to control the amount and nature of the expressed genes. these regulatory proteins bind to dna and send signals that indirectly control the rate of gene expression

explanation: