What would be the most likely effect if the side chain of an amino acid group was unable to vary its structure

The soviet union beat the us to the first successful launch, with the october 4, 1957, orbiting of sputnik 1, and later beat the us to have the first human in earth orbit, yuri gagarin, on april 12, 1961. the "race" peaked with the july 20, 1969, us landing of the first humans on the moon with apollo 11

Iguess i would say diagrams would be most difficult subject too correct