Matrix metalloproteinases (MMPs) are zinc-containing endopeptidases. They degrade proteins by cleavage of peptide bonds. More than twenty MMPs have been identified and are separated into six groups based on their structure and substrate specificity (collagenases, gelatinases, membrane type [MT-MMP], stromelysins, matrilysins, and others).
Confidence votes 164. Alleles are the different forms of a gene. Alleles are corresponding pairs of genes located at specific positions in the chromosomes. Together, alleles determine the genotype. Alleles which determine some aspect of the phenotype, the physical appearance of an organism, are said to be coding alleles.
So each cell also has 2 copies of a gene in general.These can be 2 equal forms or 2 different ones. These forms of a gene, eg the wildtype or it's mutant forms are called alleles. The genotype of an organism is the list of those alleles no matter what the outcome/appearance. The phenotype is the appearance of the organism by the sum of the effects of all genes and alleles. Color is a part of the phenotype.