Answer and explanation;
-Aba is a suitable replacement because Aba and Cys have approximately the same sized side chain and are similarly hydrophobic.
-However, Aba cannot form disulfide bonds so it will not be a suitable replacement if these are required.
-Alpha-Aminobutyric acid is biosynthesized by transaminating oxobutyrate, a metabolite in isoleucine biosynthesis.
The best answer is option D.
Acid rain is simply rainfall that has been rendered acidic due to water vapor reacting with nitrogen oxide ad sulphur dioxide very high up in the atmosphere.
Acid rain is not only a threat to the ecosystem and environment, but also seriously damages buildings and sculptures.
Marble and limestone are especially vulnerable to acid rain. This is because the two building or construction materials contain calcite which is easily dissolved by acid.
Concrete surfaces and paint finishes are also seriously damaged by acid rain.
mid-oceanic ranges I believe.
