In biochemistry, a consecutive series of chemical reactions (where the product of one reaction is the reactant of the next reaction) form metabolic pathways. These reactions are often catalyzed by protein enzymes.hemical reactions happen at a characteristic reaction rate at a given temperature and chemical concentration.
The digestive system of an ascarid consists of four parts: Alimentary Canal, Mouth, Pharynx, and Intestine. The alimentary canal compromises a short pharynx or esophagus representing the foregut, a long intestine or mod-gut, and a short rectum or hind gut.he stomodeum consists of the âmouth and lipsâ, buccal cavity, and the pharynx (esophagus). Each of these regions are used extensively in taxonomy as well as classification of nematodes, and for providing as indication of feeding habit or trophic group.
The type of epithelium present reflects the function of the particular segment of the alimentary canal. The lamina propria consists of loose connective tissue, with numerous blood and lymphatic vessels, and an abundance of diffuse lymphoid tissue.n most of the digestive tract, the muscularis externa consists of an inner circular and outer longitudinal layer of smooth muscle. The inner circular layer is arranged in a tight spiral, and its contraction results in the mixing of food by constricting the lumen of the tube.