The enzyme lactase occurs in the membranes of the epithelial cells that line the small intestine. It is made from one polypeptide, which folds to form three regions. • an active site with the free amino group on the outside of the cell • a short region within the membrane • a short region within the cell What type of amino acid would be present in each of the three regions?
- Aoutside the cell: hydrophilic; inside the membrane: hydrophobic; inside the cell: hydrophilic
- Boutside the cell: hydrophilic; inside the membrane: hydrophobic; inside the cell: hydrophobic
- Coutside the cell: hydrophobic; inside the membrane: hydrophilic; inside the cell: hydrophobic
- Doutside the cell: hydrophobic; inside the membrane: hydrophobic; inside the cell: hydrophilic