Digestion and absorption Flashcards
What is digestion?
Secretion of enzymes that hydrolyse large, insoluble molecules to smaller, soluble molecules for absorption and transport
What is the stomach?
A muscular sac that secretes enzymes from the inner layer (specifically protease)
What is the ileum?
A long muscular tube that further digests food molecules
What does the large intestine do?
Absorbs water, most of which is from the secretions of many digestive glands
What is egestion?
The removal of faeces from the anus after being stored in the rectum
What enzyme(s) do salivary glands secrete?
Amylase, which hydrolyses starch into maltose
What is the pancreas?
A large gland situated below the stomach, that produces pancreatic juices
What enzymes are within pancreatic juices?
Protease, lipase and amylase
What are the two stages of digestion?
Physical and chemical digestion
What is physical digestion?
Breaking of large food, by structures such as teeth, which provide large surface area for chemical digestion, the churning in the stomach is also physical digestion
What is chemical digestion?
Hydrolysis of large insoluble molecules into smaller soluble ones, carried out by enzymes
What does amylase do?
Hydrolyses the alternate glycosidic bonds of the starch molecule to produce the disaccharide maltose
How is maltose hydrolysed?
By the disaccharidase maltase, into alpha glucose molecules, in the ileum lining
What do mineral salts in saliva do?
Maintain the pH at around neutral, which is optimum for amylase
How does pancreatic amylase maintain a neutral pH?
Alkaline salts are produced by both the pancreas and the intestinal wall, so amylase can function