A large case-control study looked at the role alcohol plays in the development of esophageal cancer. Data from 500 cases and the 775 controls are displayed below. Information about food and alcohol consumption was gathered by interview. Researchers looked at the relationship between consuming 80 or more grams of alcohol(equivalent to a six-pack of beer or a bottle of wine) per day and the development of this cancer.

Lactase is essential for digesting lactose in milk. this enzyme is specific for this sugar. why? molecules and active sites vary in size; only properly sized molecules can fit.there is a precise compatibility between the active site and the lactose molecule.specificity refers to the action of the enzyme, such as hydrolysis, and relatively few molecules can be hydrolyzed.reaction-specific enzymes assume a fit by folding around the most numerous substrate molecules.