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24 Cards in this Set
- Front
- Back
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Where do carbohydrates and proteins go to after they are absorbed from the GI tract?
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Portal vein to liver for processing
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Where do lipids go after they are absorbed from the GI tract?
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Bloodstream
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In the absorptive phase where is energy mainly obtained from?
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Glucose
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When does the liver synthesis TAGs?
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When there is so much glucose after a meal that glycogen cannot account for all of it. Liver has to make TAG to compensate
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Where do the TAGs go that the liver has synthesised?
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Some stored in liver
Most released into bloodstream (very low density lipoproteins) |
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What happens to the VLDL made by the liver when it is needed to be used by cells?
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Broken down by lipoprotein lipase from very low density lipoproteins to fatty acids
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What is lipoprotein lipase stimulated by?
In which type of cells does this occur |
Insulin
Adipocytes |
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Which cells may use the fatty acids broken down by LPL?
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Adipose - TAG synthesis and storage - insulin-dependent
Body tissue (muscle) - fatty acids used as fuel - insulin-independent |
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What is glucose converted to in muscle cells?
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Glycogen
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What is glucose converted to in adipocytes?
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Glycerol and fatty acids to make TAGs
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What is important about the conversion of glucose to fatty acids in adipose tissue?
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It is IRREVERSIBLE
Fatty acids cannot be converted to glucose |
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don't forget the remnant
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remnant
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Where are chylomicrons and VLDLs produced?
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Chylomicrons - intestinal enterocytes
VLDLs - liver |
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When are chylomicrons and VLDLs produced?
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Chylomicrons - absorptive phase
VLDLs - continuous production |
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What type of TG do chylomicrons and VLDLs carry?
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Chylomicrons - dietary TG
VLDLs - endogenous TG (made from glucose when glycogen store is too high) |
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What happens to chylomicron and VLDL remnants?
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Chylomicron remnant - taken up by liver
VLDL remnant - taken up by liver or converted to LDL |
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What happens to the chylomicron and VLDL remnants taken up by liver and what happens to VLDL remnants processed to LDLs?
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Taken up by liver - broken down into constituent parts (may be used in bile)
LDLs - used to carry cholesterol to peripheral tissues |
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What do LDL and HDL do?
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LDL - carries cholesterol to peripheral tissues
HDL - carries cholesterol back to liver from peripheral tissues |
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What might peripheral tissues use cholesterol for?
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Plasma membranes
Steroid hormones Bile acids |
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Is it good to have a high HDL:LDL ratio?
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Yes
Less risk of atherosclerosis, coronary heart disease etc. |
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What does this diagram represent?
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Processing of amino acids in liver
Liver proteins Plasma proteins Deamination and processing Protein synthesis in other tissues |
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What happens if there is an excess of dietary protein?
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Mammals do not store protein
Deaminated and carbon skeleton used as fuel, or converted to glucose/glycogen/fat |
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How do carnivores obtain glucose?
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Gluconeogenesis from amino acids
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What are the products of deaminating an amino acid?
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Ketoacid
NH4 - converted to urea in liver -> renal excretion |
