What essential role do amino acids play in plants?

Amino acids are crucial to plant biology primarily because they are the building blocks of proteins. Proteins are essential for several plant functions, including growth, enzyme activity, and structural integrity. Each protein is made up of a specific sequence of amino acids, and the order of these amino acids determines the protein's structure and function.

In plants, proteins serve various roles, such as catalyzing biochemical reactions (as enzymes), transporting molecules, providing structural support (like in cell walls), and responding to environmental stressors. Without amino acids, plants would be unable to synthesize the proteins necessary for these vital processes, which would adversely affect their growth and health.

The other choices refer to important aspects of plant biology but do not pertain directly to the fundamental role of amino acids. Water retention is more closely associated with other molecules such as polysaccharides and plant structures. Root development involves a complex interplay of hormones and environmental factors, while act as plant hormones pertains to compounds like auxins and gibberellins rather than amino acids directly.