Adapted from "Nelson 11" Text, pg. 229.
| Table 1: Physical and Chemical Digestion | |
| Organ | Function |
| mouth | chewing of food and digestion of starch by salivary amylase |
| esophagus | transport of food from mouth to stomach; lubricated by mucus |
| stomach | storage of food and initial digestion of proteins + fats; production of the hormone gastrin (response to protein) that stimulates stomach's gastric glands to release gastric juice (including pepsin and HCl) |
| small intestine | continued digestion of carbohydrates, proteins, lipids; most absorption of nutrients; production of the hormone secretin (response to HCl) that stimulates pancrease to release bicarbonate; production of the hormone CCK (response to fat) that stimulates gall bladder to release bile |
| pancreas | production of digestive enzymes that act in small intestine; production of the hormones insulin and glucagon which regulate blood sugar; production of bicarbonate that neutralizes stomach acid in small intestine |
| large intestine | absorption of water; production of some vitamins; storage of undigested food |
| Table 2: Substances Involved in Digestion | |
| Organ | Secretion and Function |
| salivary glands | salivary amylase - converts starch (a polysaccharide) to maltose (a disaccharide) |
| esophagus | mucus - helps movement of food |
| stomach |
hydrochloric acid - converts pepsinogen to pepsin and kills microbes
pepsinogen - when converted to pepsin, initiates digestion of proteins (long chains of amino acids) to polypeptides and peptides (shorter chains of amino acids)
lipase - converts lipids (eg. triglycerides) into glycerol and fatty acids
mucus - protects stomach from pepsin and HCl renin - coagulates proteins in milk to slow movement |
| pancreas; small intestine |
pancreatic amylase - converts starch (a polysaccharide) to maltose (a disaccharide)
bicarbonate - neutralizes HCl from stomach
enterokinase - converts trypsinogen to trypsin
trypsinogen - when converted to trypsin, converts proteins into peptides
erepsin - converts peptides into amino acids
lipase - converts lipids (eg. triglycerides) into glycerol and fatty acids
maltase - convets maltose (a disaccharide) into two glucose (a monosaccharide)
sucrase - convets sucrose (a disaccharide) into glucose and fructose (monosaccharides)
lactase - convets lactose (a disaccharide) into glucose and galactose(monosaccharides)
|
| liver | bile - emulsifies fat (large globules into smaller ones for lipase to work) |
| gall bladder | bile - stores concentrated bile from liver |
| large intestine | mucus - helps movement of food |