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.
The different forms of a gene are called alleles. If both alleles are are identical, the organism is said to be homozygous for that trait. For instance, Mendel's purebred tall plants possessed two tall alleles and are said to be homozygous tall.hen expressing dominant and recessive alleles, the dominant allele is always written as a capitalized letter, and the recessive allele as the same letter, but lower case.