What type of chemical reaction builds large molecules from smaller ones?

Anabolic reactions are basically taking what's in your food and forming large complex molecules. The context you've all heard anabolic before in is that athletes will take anabolic steroids for growth. When sugars are joined together to create glycogen, that's anabolism. When you join amino acids to make proteins, like in your muscles, that's an anabolic reaction. When fatty acids in your food are joined to form a triglyceride, that's an anabolic reaction.