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26 Jan. 2010. Digestion_Reg.ppt. 2. Chemical Digestion. Depends on enzymes (hydrolytic)Enzyme activity depends onPresence of substrateConcentration of substrateConcentration of enzymeTemperaturepHPepsin @ pH = 2.0Trypsin @ pH = 7.2. 26 Jan. 2010. Digestion_Reg.ppt. 3. Chemical Digestion. Enz
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1. 26 Jan. 2010 Digestion_Reg.ppt 1 Regulation of Digestion
2. 26 Jan. 2010 Digestion_Reg.ppt 2 Chemical Digestion Depends on enzymes (hydrolytic)
Enzyme activity depends on
Presence of substrate
Concentration of substrate
Concentration of enzyme
Temperature
pH
Pepsin @ pH = 2.0
Trypsin @ pH = 7.2
3. 26 Jan. 2010 Digestion_Reg.ppt 3 Chemical Digestion Enzymes secreted only when appropriate substrates are present in stomach/duodenum.
Digestion takes time
Necessary to regulate movement of chyme
Controls concentrations of substrates and enzymes
Controls pH
Pyloric sphincter is key control point.
4. 26 Jan. 2010 Digestion_Reg.ppt 4 Long & Short Reflexes Stimuli Sight, smell, taste, thought of food Stretch of mucosa Chemical changes in lumen Long reflexes through CNS Short reflexes by enteric nerve plexus