A peptide bond is a covalent bond formed between two amino acids. Living organisms use peptide bonds to form long chains of amino acids, known as proteins. Proteins are used in many roles including structural support, catalyzing important reactions, and recognizing molecules in the environment. A peptide bond is therefore the basis of most biological reactions. Forming peptide bonds is a requirement for all life, and the process is very similar in all forms of life.
They could improve the experiment that they made by adding another variable such as: watering the plants with fresh water. This way they could have a better comparison how plants grow based on the type of water they are exposed with.
