3.3 Organisms exchange substances with their environment Flashcards
what are large biological molecules broken down into
smaller molecules
what is the role of digestion
breaks larger molecules into smaller molecules
where is amylase produced
-salivary glands
- pancreas
where is amylase released
into the mouth
into the small intestine
what does amylase hydrolyse starch into
maltose
what does starch get hydrolysed into
maltose
where are membrane bound disaccharides found
attached to the epithelial cells lining the ileum of the small intestine
what does maltase hydrolyse maltose into
glucose and glucose
what does sucrase hydrolyse sucrose into
fructose and glucose
what does lactase hydrolyse lactose into?
galactose and glucose
where are bile salts produced
liver
what do bile salts do
the emulsify lipids into smaller droplets
what do small lipid droplets provide
- they increase the surface area of lipids
-speeds up the action of lipase
where is lipase made
pancreas
where is lipase released
the small intestine
what does lipase hydrolyse lipids into
monoglycerides + fatty acids
what bonds do lipase break
ester bonds
what components form micelles
monoglycerides
fatty acids
bile salts
what do monoglycerides, faaty acids and bile salts stick together to form
micelles
what is the role of endopeptidases
-hydrolyse peptide bonds within a protein.
- breaks proteins into 2 or smaller peptides
what is the role of exopeptidases
hydrolyse peptide bonds at the end of proteins
removing an amino acid
what is the role of dipeptidases
hydrolyse peptie bonds between a dipeptide
where is dipeptidases found
membrane bound in ileum
describe where the concentration gradient established when sodium is actively pumped out of the cell into the blood
high concentration of sodium in lumen than epithelial cells.
describe where the concentration gradient is established when glucose is co-transported from the lumen into the epithelial cells
higher concentration of glucose in epithelial cell than blood
describe the mechanism of the absorption of micelles
- monoglycerides and fatty acids diffuse out of micelles into epithelial cells . [lipids are soluble]
- monoglycerides and triglycerides recombine to triglycerides which aggregate into globules.
- globules coated to form chylomicrons
gobulars coated with proteins are called….
chylomicrons
what do micelles contain
bile salts
fatty acids
monoglycerides
describe the process involved in he absorption and transport of digested lipid molecules from the ileum into lymh vessels
micelles contain bile salts and lipids
they bring/release fatty acids/monoglycerides to the cells lining the lumen
fatty acids are absorbed by diffusion
triglycerides are formed
vesicles move to the membrane
where does digestion occur
small intestine
