Absorption And Digestion Flashcards
What enzyme catalysed the breakdown of alpha 1-4 bonds within amylose?
Which enzyme breaks down alpha 1-6 bonds?
Amylase,
Isomaltase
What brush border enzymes catalyse the breakdown of lactose and sucrose?
Lactase and sucrase
Which transporter is responsible for the absorption of glucose and galactose?
Which transporter absorbs fructose?
SGLT1
GLUT5
Which transporter facilitates the movement of sugars into the blood?
GLUT 2
What enzyme begins protein digestion in the stomach?
Pepsinogen secreted by chief cells
Converted to pepsin by acidic conditions
Which enzyme activates other pancreatic proenzymes in the intestine?
Trypsin. Converted from trypsinogen by enteropeptidases.
Which endopeptidases help breakdown proteins in the intestine?
Trypsin
Chymotrypsin
Elastase
Which exopeptidases are found in the intestinal lumen?
Carboxypeptidase A and B
How are amino acids absorbed at the brush border?
How are dipeptides and tripeptides absorbed
Symported with sodium ions.
Transported across the PepT1 transporter for digestion by cytosolic peptidases
How is water secreted by the intestine?
Following solvent drag generated by the excretion of Cl- ions through the CFTR protein, which responds to rises in cAMP
Where is vitamin B12 absorbed?
What other molecule is needed to absorb it?
Terminal ileum.
Intrinsic factor, produced by the stomach parietal cells.
What are common symptoms of vitamin B12 deficiency?
Neurological problems
Megaloblastic anaemia
Why does lactose intolerance occur?
Deficiency of lactase, which degrades after age 2, means lactose remains in the intestine and drives movement of water into the lumen, causing diarrhoea. May be fermented by gut flora and cause bloating and discomfort.
What is coeliac disease?
How is it managed?
Immunological response to gliadin fraction of gluten causing diarrhoea, anaemia, weight loss and neurological symptoms. Managed by a gluten free diet.
