The digestive system Flashcards
What is secreted out of salivary glands during carbohydrate breakdown
Mineral Salts - Maintain pH of 7
Carbohydrase - Amylase to hydrolyse starch into disaccharide
What does the stomach acid do for carbs
Denature amylase
Muscle on stomach helps churn food
What does the pancreas do for carbs
Secretes pancreatic juice containing alkaline salts to increase pH to 7 + Secretes enzyme (amylase)
What happens in the Ileum for carbs
Disaccharide is hydrolysed via disaccharidease into monosaccharides
Enzymes are membrane bound on ileum
e.g maltose hydrolysed by maltase
How does physical digestion occur and why
Teeth help to break large substances into smaller substances
Muscle in stomach helps to churn food
This makes it easier to swallow and increases surface area of enzyme action and absorption
How are Lipids hydrolysed
Use of Lipase
Hydrolyses into Monoglyceride and 2Fatty acids
What happens during emulsification of a lipid
Big lipid droplet it emulsified by bile salts
Emulsified into micelles that increase SA for enzyme action
How is a polypeptide hydrolysed
Endopeptidase Hydrolyses peptide bonds in the centre of the polypeptide chain
Exopeptidase hydrolyses peptide bonds at the end of a chain
Dipeptidase are membrane bound and hydrolyse dipeptides into amino acids
How are triglycerides absorbed into the body
Micelle carries monoglyceride, 2 fatty acids and bile salt to lumen of ileum
Micelle collided with epithelial cell membrane, releasing contents and so they diffuse into cell as they are non-polar
Monoglyceride and fatty acids enter smooth endoplasmic reticulum and reformed into a triglyceride
Triglyceride enters golgi body and is secreted via a chylomicron with lipoprotein and cholesterol
Leave cell via exocytosis
Diffuse into Lacteal (lymphatic capillary) in the villus
Diffuse into capillary and are hydrolysed by membrane bound enzymes on the endothelial capillary cells
Where are bile salts produced and secreted?
Bile salts produced by liver, secreted by gallbladder
