Biology · Biological Molecules

Glycine and alanine are the two simplest amino acids. Glycine is the smallest amino acid, with just a single hydrogen atom as its side chain, while alanine has a slightly larger side chain consisting of a methyl group. Both of these amino acids are important building blocks for proteins and are commonly found in a variety of organisms. So option C is encircled.

Trypsin is not an amino acid. It’s a digestive enzyme made from many amino acids.

Glycine is a simple amino acid. It has the smallest side chain, just a single hydrogen.

Trypsin is not a simple amino acid. It’s a protein enzyme.

Alanine is a simple amino acid.

Glycine and alanine are considered simple amino acids because their side chains are very small. Glycine has just a single hydrogen as its side chain, and alanine has a small methyl group. Their structures are uncomplicated compared to other amino acids, so this option is correct.

Glutamate is not the simplest amino acid because it has a larger, acidic side chain, so it doesn’t fall into the “simple” category.