Question

why are all enzimes proteins but not all proteins are enzimes?

Answer 1

Enzymes /ˈɛnzaɪmz/ are both proteins and biological catalysts (biocatalysts). Catalysts accelerate chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products.Enzymes are biological molecules (proteins) that act as catalysts in complex reactions. But all proteins do not act as catalysts. So all enzymes are proteins but all proteins are not enzymes. The enzymes have an active site where substrates can bind.Metallothionein is a cytoplasmic protein, in an adult liver, it is localized mainly in the cytoplasm. In human fetus, metallothionein is localized in hepatocyte nuclei.