Help
Options
Question
Cholesterol Synthesis Starting materials
click to flip
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't know
Question
HMG-CoA reductase
Remaining cards (47)
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
WVSOM - Biochem
Cholesterol and Bile Acid Synthesis
| Question | Answer |
|---|---|
| Cholesterol Synthesis Starting materials | Acetyl CoA NADPH ATP |
| HMG-CoA reductase | rate limiting step (target of drug therapy) |
| Products of cholesterol synthesis | Cholesterol NADP+ ADP |
| Location of Cholesterol synthesis | hepatocytes |
| regulated enzyme of cholesterol synthesis | HMG CoA reductase |
| Increasing levels of cholesterol __________ cholesterol synthesis | decreases |
| HMG CoA is active when | dephosphorylated |
| HMG CoA is dephosphorylated with ___________ insulin to glucagon levels. | high |
| HMG CoA is inactivated by ____________ and is then _____________ | Glucagon; phosphorylated |
| Most significant factor in regulation of cholesterol biosynthesis | decreasing HMG CoA reductase synthesis |
| Proteolysis of HMG CoA reductase increases as ____________ | sterol levels rise |
| Which drug class inhibits this enzyme | statins |
| Extrahepatic cholesterol synthesis | occurs under certain pathological conditions |
| Why is cholesterol esterified | regulation |
| where is cholesterol esterified | on lipoprotiens and in cells |
| How does esterification change regulation | cholesterol ester CANNOT regulate HMG CoA reductatse |
| Two enzymes that esterize cholesterol | LCAT (Lecithin) ACAT (acyl CoA) |
| LCAT | Esterifies cholesterol on lipoprotein that can be transferred from HDL to LDL |
| ACAT | esterifies cholesterol within the cell |
| Extrahepatic cholesterol synthesis | under certain pathological conditions |
| Where are cholesterol esterified/de-esterified in cells? | lipoproteins |
| Esterifcation of cholesterol | changes the properties of cholesterol especially with regard to its control functions |
| LCAT | Lecithin: chelesterol acyl transferase Esteerifies cholesterol on lipoproteins |
| What is transfered to LDL and HDL | Esterfied cholesterol |
| ACAT | esterfies cholesterol within the cell |
| Cholesterol esterase | reveses LCAT and ACAT esterification |
| Bile Salt Synthesis Location | hepatocytes |
| Starting compounds of Bile Salts | Cholesterol, ATP, NADPH |
| 4 conjugated bile salts | taurocholic glycocholic taurochenocholic glycohenocholic acids |
| Conjugation of bile salts increases ____________ | solubility |
| Solubility enables bile salts to act as | detergents |
| Conjugated bile salts composed of | primary bile salts, cholic acids and chenocholic ascid conjugated to taurine or glycine which are hydrophobic |
| How much bile salts are recycled | > 95% |
| Liver synthesis of bile acid _____ g/day | .2 - .6 |
| Amount of bile salts reabsorbed | 12-32 g/day |
| bile removed by feces | .2-.6 g/day |
| Why would we want to decrease bile salt reabsorption | drugs which bind to bile acids prevent their reabsorption to increase cholesterol excretion |
| Cholesterol esterase | reverses LCAT and ACAT by de-esterifying cholesterol |
| Bile Salt Exrection | in feces |
| Primary Bile Salts | chenocholic acid and chlic acid |
| Location of bile acid synthesis | hepatocytes |
| starting compounds of bile acid synthesis | cholesterol ATP NADPH |
| Controlled step of bile acid salts | products and substrate!!!! |
| Products of bile acid synthesis | cholic acid and chenocholic acids |
| Conjugated bile salts | primary bile salts bound to hydrophobic taurine or glycine |
| 4 conjugated bile salts | taurocholic glycocholic taurochenocholic glyochenocholic acids |
| Bile Salts recycled | > 95% 12-32 g/day |
| Why would we want to pharmachologically bind drugs to bile acids | to prevent reabsorption to increase cholesterol excretion |
Created by:
tjamrose
Popular Biochemistry sets