digestion Flashcards
what is digestion
During digestion, large biological molecules are hydrolysed to smaller molecules that
can be absorbed across cell membranes.
what are the mechanisms for absorption of products of digestion
co-transport mechanisms
the role of micelles for the absorption of lipids
what is the ileum and its role
The ileum is a long muscular tube (the final part of the small
intestine), food is further digested in the ileum by enzymes that
are produced by its walls and by glands that pour their secretions
into it.
where is amylase found
the mouth ,pancreas and small intestine
what is the role of amylase in the hydrolysis of carbohydrates
amylase is hydrolyses the
alternate glycosidic bonds of the starch molecule to produce the disaccharide maltose.
maltose is then hydrolysed into two units of alpha glucose by a second enzyme, a
disaccharidase called maltase.
describe the digestion of fats
lipases hydrolyse the ester bond found in triglycerides to from fatty acids and monogylcerides.
where is lipase found
pancreas
what are the two main enzymes involved in digestion of protein
endopeptidase -hydrolyses peptide bonds in the middle of amino acid chain
exopeptidase-hydrolyses peptide bonds on the exterior of amino acid chain.
how is the ileum adapted for digestion
the walls of the ileum have projection called villi
the villi
increase surface area
has thin walls so short diffusion pathway
has a good blood supply
epithelial cells has microvilli
Describe the processes involved in the absorption and transport of digested lipid molecules from the ileum into lymph vessels
1.Micelles contain bile salts and fatty acids/monoglycerides;
2.Make fatty acids more soluble in water
3. Fatty acids are absorbed by diffusion
4. Triglycerides reformed in cells
5. Vesicles move to cell membrane;
