digestio and absorption Flashcards
where does carbohydrate digestion begin and by which enzyme?
in the mouth via salivary amylase
what does salivary amylase do?
hydrolyses a-1,4-glycosidic bonds (present between glucose monomers)
which enzymes are present in the small intestine that digest carbs
lactase
sucrase
maltase
what would be absent in a lactose intolerance?
lactase
what is lactose broken into?
galactose and glucose
what is sucrose broken into?
sucrose and glucose
what is maltose broken into?
glucose
how can glucose and galactose be absorbed at low concentrations
sodium and glucose transporter (SGLT 1)
how are glucose, fructose and galactose taken out of the enterocyte?
GLUT 2 transporter
how is fructose absorbed?
GLUT 5
where does protein digestion occur
stomach
where is HCL produced?
parietal cells
what activates pepsin from pepsinogen?
HCl
what does pepsin do?
degrades peptide bonds between proteins
which pancreatic enzymes help aid protein digestion?
tyripsin
chymotrypsin
carboxypeptidase
elastase
what does chymotrypsin do?
hydrolysis of the peptide bond
what does carboxypeptidase do?
hydrolysing at the carboxyl end of the polypeptide
what does elastase do?
break down elastin
what does tyripsin do?
cleaving peptide bonds
what is the role of brush border enzymes?
break down small polypeptides
how are amino acids taken in?
sodium transporters
where is lingual lipase present?
present in the mouth and gastric lipase in the stomach as well as pancreatic lipase present from the pancreas
what is the role of bile?
allows for emulsification of the fat droplets which increases the surface area to allow the lipase to act
what is formed In the breakdown of lipids?
monoglycerides and free fatty a
what is formed following the absorption of monoglycerides?
chylomicrons - then absorbed into the lymphatic system
what do G cells produce?
gastrin
