| Describe the digestion of starch | Starch enters the mouth and is hydrolysed into maltose by salivary amylase. In the duodenum it is again hydroylsed into maltose by pancreactic amylase which is breaking the glycosidic bonds . then in the ileum the maltose is hydrolysed by membrane bound maltase into alpha glucose |
| Describe the digestion of proteins | In the stomach the endopeptidase breaks the internal peptide bonds of the protein forming smaller polypeptide chains. In the duodenum the smaller polypeptide chains are hydrolysed by exo and endo peptidase to release amino acids and di peptides. therfore in the ileum membrane bound dipetidase hydrolysed the peptide bond of the dipeptide to form amino acids. |
| Digestion of lipids | the liver makes bile salts that is stored in the gallbladder . in the duodenum the bile salts emulsify these fats into smaller fats. pancreatic lipase hydrolyses ester bonds in lipids to form glycerol and fatty acids. In the ileum the membrane bound lipase hydrolyse the lipids further into 3 fatty acids and one glycerol and micelles |
| Absorption of glucose | The SODIUM POTASSIUM PUMP allows for sodium ions to be actively transported out of the cell , atp is required as it is against the concentration gradient . this lowers the sodium ion concentration inside the epithelial cell creating a conc gradient.
2. The glucose and sodium ions from the lumen bind to NA+/GLIUCOSE CO TRANSPORT PROTEINas they are facilitated diffused into the cell from (high-low )
3. GLUCOSE CHANNEL PROTEIN allows glucose to be absorbed from the ep cell into the blood by facilitated diffusion |
| What do the proteins names change to when its proteins absorption | 1. Na+/K pump
2. Na+/amino acid co transport protein
3. Amino acid channel protein |
| Absorption of fats | 1. Micelles form - complex of bile salts , glycerol and fatty acids . Micelles bring glycerol and fatty acids to the cell membrane . glycerol and fatty acids diffused into cell across bilayer
2. ser synthesises to form lipids
2.5 golgi processes triglycerrides with a protein to form chylomicrons in a vesicle . vesicle realeases them so they can diffuse into lacteals.
3. fluid in lacteals drains into bloods |
| The structure of the ileum | Many long folds called villi . Thick smooth muscle layer , thin muscle layer end epithelium |
| What is the Villi | The villi are lined with a single layer of epithelial cells. Many small branching blood vessels called capillaries and long lymph vessels called a lacteal |
| an enzyme that catalyzes the hydrolysis of sucrose into glucose and fructose | Sucrase
Maltose
Lactose
Lipid
Dipeptide |
| Absorption of digestive products | Molecules move into the lumen , moves across microvilli of epithelial cells , moved across endothelial cells lining the capillary unit the blood |
