Digestion and absorption Flashcards
what happens during digestion?
large biological molecules are hydrolysed into smaller molecules tat can be absorbed across cell membranes
what enzyme hydrolyses starch to maltose?
amylase
where is amylase produced
salivary glands, released into the mouth
pancreas, released into the small intestine
what enzyme hydrolyses maltose (disaccharide) to glucose (monosaccharide)
maltase
where do maltose molecules get hydrolysed into glucose molecules?
the small intestine
where are maltase enzymes located?
attached to the epithelial cells lining the ileum of the small intestine
whats the funtion of maltase
hydrolyse glycosidic bonds between maltose
what are the three main disaccharides?
maltose
fructose
galactose
what are the three main disaccharidases?
maltase
sucrase
lactase
what enzyme hydrolyses lipids?
lipase
where are bile salts produced?
the liver
what is the role of bile salts?
emulsify lipids to smaller lipid droplets (increases surface area) help speed up the action of lipases
where is lipase made and released into?
made in the pancreas, released into the small intestine
what’s the role of lipase?
hydrolyse lipids into monoglycerides and fatty acids, breaking ester bonds
what are micelles?
monoglycerides, fatty acids and bile salts stuck together to be absorbed in epithelial cells
what’s the role of endopeptidases?
hydrolyse peptide bonds within a protein (centre)
break protein into 2 or smaller peptides
what’s the role of exopeptidases?
hydrolyse peptide bonds at the ends of the protein molecule
removing a single amino at the ends
role of dipeptidiases?
hydrolyse peptide bond between a dipeptide
> 2 amino acids
suggest and explain why the combined actions of endopeptidases and exopeptidases are more efficent than exopeptidases on their own
1) endopeptidaes hydrolyse internal peptide bonds
2) more ends increase surface area
how are sodium ions actively transported out of epithelial cells lining he ileum into the blood?
1) sodium ions actively transported out of epthelial cells lining the ileum, into the blood, by the sodium potassium pump
2)sodium ions and glucose move my facilitated diffusion into the epithelial cell from the lumen via a co transporter protein
3)creating a concentration gradient of glucose (high in cell than blood)
4) glucose moves into blood via facilitated diffusion through a protein channel
