Digestive System Flashcards
What is digestion?
The chemical breakdown of large insoluble molecules (polymers) which cannot be absorbed into small soluble molecules (monomers) that can be absorbed and assimilated by the small intestines
What are digestive juices?
Hydrolysis enzymes and other molecules that facilitate digestion which are produced in the gland cells
Carbohydrates hydrolysed into… by…?
Into simple sugars by carbohydrases
Fats are hydrolysed into… by…?
Into fatty acids, glycerol and monoglycerides by lipases
Polypeptides and proteins hydrolysed into… by…?
Into amino acids by proteases
What is produced in the salivary glands?
Salivary amylase which breaks glycosidic bonds converting starch into maltose
What is produced in the stomach?
Endopeptidases (e.g. pepsin) and exopeptidases which breaks peptide bonds converting proteins and polypeptides into amino acids
What is produced in the pancreas?
Pancreatic amylase, Lipases and exopeptidases
What is produced in the ileum?
Membrane-bound dipeptidases and dissacharidases e.g. maltase (dissacharidase) which breaks glycosidic bonds converting maltose to glucose
Protease examples
Endopeptidases, exopeptidases and dipeptidases
Key organs 1: Salivary glands
Secrete salivary amylase converting starch to maltose and carries out mechanical digestion which chews food into smaller prices to increase surface area for enzymes
Key organs 2: Oesophagus
Food travels down towards the stomach
Key organ 3: Stomach
Food is mixed with gastric juice which is acidic to kill microorganisms and contains endopeptidases and exopeptidases which hydrolyses polypeptides to dipeptides. Also stores HCl to denature salivary amylase only
Key organ 4: Liver
Bile salts are produced for lipid digestion to emulsify fats
Key organ 5: Pancreas
Secretes pancreatic juice containing amylase (and other carbohydrases), endo and exopeptidases + lipases
Key organ 6: Small intestine
Villi adapted to provide large surface area for absorption. Membrane-bound maltase embedded in the epithelium cell membrane, which hydrolyses maltose to glucose so it’s available for absorption. Also contains sucrase, lactase and dipeptidase enzymes
Key organ 7: Large intestines
Absorb water and salts from undigested food + get rid of waste
Key organ 8: Rectum
Secrete waste
