This video lecture from Enzymes (F.Sc. first year Biology) covers: Enzymes – The biocatalyst of living system made up of proteins, having active sites and sometimes cofactor and coenzymes for proper function. Models of enzyme action. (Lock and Key model, Induce fit Model). Find more e-learning material and educational video lectures in Urdu at maktab.pk. These videos are free to use for promotional and commercial purpose by keeping the credits to Maktab.