Humans have two sources of cholesterol: absorption from ingested food and de novo synthesis by the liver. High levels of cholesterol in the blood correlates with cardiovascular disease, but cholesterol is required to regulate membrane fluidity and is a precursor for important molecules like steroids and bile acids. Thus, humans evolved several types of regulation of cholesterol levels. How does the human body compensate for excess consumption of cholesterol in the diet? Transcription of the HMG-CoA reductase gene decreases in the presence of high intracellular cholesterol. Eating a cholesterol-rich meal causes the hypothalamus, the hunger center of the brain, to signal satiety. High cholesterol concentrations upregulate the number of serum transport proteins that deliver cholesterol to the liver for degradation.

Humans have two sources of cholesterol: absorption from ingested food and de novo synthesis by the liver. High levels of cholesterol in the blood correlates with cardiovascular disease, but cholesterol is required to regulate membrane fluidity and is a precursor for important molecules like steroids and bile acids. Thus, humans evolved several types of regulation of cholesterol levels. How does the human body compensate for excess consumption of cholesterol in the diet? Transcription of the HMG-CoA reductase gene decreases in the presence of high intracellular cholesterol. Eating a cholesterol-rich meal causes the hypothalamus, the hunger center of the brain, to signal satiety. High cholesterol concentrations upregulate the number of serum transport proteins that deliver cholesterol to the liver for degradation.

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Description: Humans have two sources of cholesterol: absorption from ingested food and de novo synthesis by the liver. High levels ofcholesterol in the blood correlates with cardiovascular disease, but cholesterol is required to regulate membrane fluidity and is

Concepts of Biology

1st Edition

ISBN:9781938168116

Author:Samantha Fowler, Rebecca Roush, James Wise

Publisher:Samantha Fowler, Rebecca Roush, James Wise

Chapter9: Molecular Biology

Section: Chapter Questions

Problem 10RQ: Control of gene expression in eukaryotic cells occurs at which level(s)? a. only the transcriptional...

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