The Rgroup or side chain of the amino acid serine is amino a

The R-group, or side chain, of the amino acid serine is amino acid leucine is -CH_2-CH-(CH_3)_2. Where would you expect to find these amino acids in a globular protein in aqueous solution? A) Serine would be in the interior, and leucine would be on the exterior of the globular protein. B) Leucine would be in the interior, and serine would be on the exterior of the globular protein. C) Serine and leucine would both be in the interior of the globular protein. D) Serine and leucine would both be on the exterior of the globular protein.

Solution

The R group or side chain of the amino acid serine is -CH2-OH. The R group or side chain of the amino acid leucine is -CH2-CH-(CH3)2. Where would you expect to find these amino acids in a globular protein in aqueous solution?

B.Leucine would be in the interior, and serine would be on the exterior of the globular protein.

With respect to globular proteins, the amino acid side chains will be seen distributed based on their polarity, interior side; we will have non-polar residues like Met, Phe, Ile, Leu and Val.

On the exterior side we will have Arg, Lys, His, Asp and Glu. On the surface uncharged polar amino acid residues like Trp, Tyr, Gln, Asn, Thr and Ser will be found. The arrangement will help the polar side chain groups on the surface of these globular proteins to make hydrogen bonds with the water molecules.