BIOMOLECULES AND ENZYMES

Detailed explanation-1: -The polarity of serine, threonine is due to the presence of hydroxyl groups; the polarity of asparagine and glutamine is due to the amide group and the sulfhydryl group (thiol group) is responsible for cysteine.

Detailed explanation-2: -The serine/threonine kinase Par1b promotes cell-cell adhesion and determines the polarity of the luminal domain in epithelial cells.

Detailed explanation-3: -Six amino acids have side chains that are polar but not charged. These are serine (Ser), threonine (Thr), cysteine (Cys), asparagine (Asn), glutamine (Gln), and tyrosine (Tyr). These amino acids are usually found at the surface of proteins, as discussed in the Proteins 2 module.

Detailed explanation-4: -Threonine is an amino acid and belongs to the class which has neutral R-groups. It has a side chain containing a hydroxyl group, making it a polar, uncharged amino acid. It is hydrophilic.

Detailed explanation-5: -Hydroxyl amino acids Serine (Ser/S) is one of three amino acids having an R-group with a hydroxyl in it (threonine and tyrosine are the others). It is coded by UCU, UCC, UCA, UGC, AGU, and AGC. Being able to hydrogen bond with water, it is classified as a polar amino acid.