Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Met.biochem L8
Lipid Digestion
| Question | Answer |
|---|---|
| Dietary fat (3 main) | -phospholipids -cholesterol esters -triglycerides |
| Dietary fat properties | -hydrophobic -poorly absorbed & digested |
| Bile acids | -from pancreas -emulsify lipids ->micelle |
| Micelles | -emulsified lipids -allows soluble enzymes to act |
| lipases | -gastric & pancreatic -hydrolyse triglycerides to form glycerol & fatty acids |
| Triglyceride hydrolysis.. | -by lipases -fatty acids & glycerol |
| Phospholipid hydrolysis... | -cholesterol -fatty acids |
| Cholesterol | -poorly absorbed in intestine |
| Short-chain fatty acids | -pass directly through gut epithelial -serum albumin transports through blood |
| Long-chain fatty acids | -fatty-acid binding protein -re-esterfied W chol. -secreted into blood as chylomicrons |
| 3 unsaturated fatty acids not synthesised by humans: | -linoleic -linolenic -arachidonic acid |
| lipid in diet... | -helps absorption of vitamin -palatable food |
| lipoprotein complex | -lipid & apolipoproteins re-packed -in liver |
| Very Low Dense Lipoproteins (VLDLs) | -released from liver -tryglyceride hydrolysed by lipoprotein lipase |
| Removal of lipid from lipoprotein... | -VLDL more dense->I/LDL -smaller -more cholesterol |
| Endocytosis of LDLs allows cells.... | -to acquire cholesterol |
| High-Density Lipoprotein (HDL) | -contain proteins from liver -remove cholesterol from cell membranes & return to liver |
| Chylomicrons | -long chain fatty acids re-esterfied with glycerol -secreted into blood |
| Glycerol->Glyceraldehyde-3-P | -Via glycerol-3P -met. gluconeogenesis -glycolytic |
| starved state triglycerides in adipose tissue.. | -hydrolysed -resp. to horm. signals -FFA & glycerol |
| Cells have membrane fatty acid-binding protein... | -accepts FFA from albumin -transfers to cytoplasmic binding protein |
| Fatty acyl coenzyme A synthatase.. | -2ATP+FFA+CoASH-->FA-CoA+2ADP+2Pi |
| FA-CoA is oxidised in... | -mit. -transported using carnitine cylce |
| other products of triglyceride breakdown.. | -glycerol -met. by glycolysis-->glycerol-3P |
| B-oxidation | -breaks 2C from FA-CoA--->acetyl-CoA -cyclical series rxns |
| Key reactions [B-oxidation] | (1)Dehydrogenation across A-B C-C bond (2)Hydration (same bond) (3)2nd dehydrogenation (B-keto grp) (4)attack by CoASH |
| (4)attack by CoASH (B-oxidation) | -form shorter FA-CoA + Acetyl-CoA |
| Reduced co-factor FADH2& NADH | -re-oxidised in mit ETC |
| Acetyl-CoA from B-oxidation can be.. | -further oxidised -TCA cycle |
| Saturated Even#FA's | -fully oxidized by B-oxidation |
| saturated Odd#FA's | -residual propionyl-SCoA(3C)-->methylmalonyl-CoA (CO2 fixation) -rearranged to succinyl-CoA |
| Unsaturated FA's | -require extra enzyme for degradation -Cis-enoyl-->trans by isomerase -E yeild lower |
| Ketone bodies | -surplus Acetyl-CoA can't be ox. by TCA -levels of oxaloacetate may be limiting |
Created by:
meglet
Popular Biology sets