The fire emoji next to a friend's name means that you and that special, special person in your life have snapped one another within 24 hours for at least two days in a row. You know, like your friendship is on fire? Or...
In adult humans, the most common hemoglobin type is a tetramer (which contains 4 subunit proteins) called hemoglobin A, consisting of two Î± and two Î² subunits non-covalently bound, each made of 141 and 146 amino acid residues, respectively. This is denoted as Î± 2 Î² 2.
For instance, let's take hemoglobin. It generally has 146 amino acids, but not all them are essential for the protein to be functional. So, if we a ask a question as to how many different amino acids are necessary for the protein to be known as the  hemoglobin  protein, then the answer depends on many things. Whenever changes in amino acid affects the physical structure of protein molecule, the affected protein becomes inactive.