Lecture 7 - Nutrition and the digestion system

This smulates the gallbladder to contract and release

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Unformatted text preview: absorbed in stomach but most in small intes,ne 51 Vertebrates gastrointes,nal system – Small intes,ne •  Glucose absorp,on –  Symporters combine the transport of Na+ and other molecules such as glucose, galactose and/or amino acids –  As sodium moves down its concentra,on gradient, the “hitchhiking” molecules moves with it 52 Regula,on of diges,on  ­ Sugars •  As carbohydrates are digested and absorbed, glucose level in the blood rises –  Beta cells in the pancreas releases insulin –  Insulin have a role direc,ng where glucose is going to be used/stored –  Sugars in excess are stored as glycogen or fats 53 Regula,on of diges,on  ­ Sugars Increases circula,ng glucagon S,mulates pancreas to secrete glucagon Breakdown of glycogen in liver Release of glucose to blood Decrease in blood glucose Increase in blood glucose Metabolic energy produc,on, fat synthesis, glycogen synthesis Uptake of glucose by cells S,mulates pancreas to release insulin Increase in circula,ng insulin 54 Regula,on of diges,on  ­ Sugars •  Diabetes –  Sta,s,cs about diabetes in the US –  Type 2 diabetes is prevented with diet and exercise but there is a gene,c component –  Body is not capable of regula,ng insulin appropriately –  Medica,on if given to enhance insulin produc,on or provide the body with insulin 55 Vertebrates gastrointes,nal system – Small intes,ne •  Fat absorp,on –  Large lipids are hydrolyzed into monoglycerides and faay acids, which can pass through plasma membrane –  Inside the cell, they get re ­ packed into chylomicrons –  Gets transported into vesicles to the lympha,c system 56 Regula,on of diges,on  ­ fats •  Hydrophobic fats get converted into chylomicrons (the largest lipoprotein par,cle in the blood) •  Lipoproteins (other than chylomicrons) are created in the liver and they are categorized by density –  The lower density the higher lipid to protein content –  High ­density lipoproteins (HDLs) •  Remove cholesterol from ,ssue and brings it to the liver to synthe,ze bile –  Low ­density lipoprotein (LDLs) •  Transport cholesterol for stor...
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This document was uploaded on 03/05/2014.

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