26 Cholesterol - Biochemistry Education BIOC 423:...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
B iochemis±ry ²E duca±ion Department±of±²iochemistry±&±Molecular±²iology University±of±New±Mexico BIOC 423± Int²oducto²y Biochemist²y Complex Lipids: Cholesterol OBJECTIVES Be able to draw the complete structure of cholesterol. Know the control step and the regulation of cholesterol biosynthesis and example inhibitors of regulated enzyme. Be able to summarize how cholesterol is synthesized from acetyl-SCoA and transported in the body. Define the biological difference between “good cholesterol” and “bad cholesterol”. Given the structure of a steroid, be able to distinguish between bile acids, steroid hormones and cholesterol. Know the physiological role for each of the three steroid classes (cholesterol, bile acids and steroid hormones). OUTLINE Overview of steroid structure and function How to distinguish between cholesterol, bile acids, and hormones "Good and Bad" cholesterol - Steroid transport Summary of steroid synthesis Synthesis of HMG-CoA HMG-CoA reductase General scheme of steroid synthesis Regulation of HMG-SCoA reductase Allosteric regulation Gene Expression Drugs - statins
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
LECTURE Steroids are undoubtedly the single class of molecules that receive the most publicity and the most “air time” on television, and generally they receive the reputation as “BAD” molecules. Steroids need a much better public relations agent because they are very important molecules in several critical, and divergent, biological functions of structure, signaling and digestion. The families of steroids are represented by three different classes of molecules. Structural (example: cholesterol) Hormones (example: steroid hormones and vitamin D derivatives) Bile acids and salts Cholesterol is often used are the parent molecule for the entire set of steroids and, in fact, it is the starting material for the synthesis of all members of the family. Based on structure alone it is relatively easy to distinguish between the different members of this family. These differences are illustrated in the following figure. HO OH OH COO D C HO B A HOH 2 C O OH HO O Cholesterol Hormone (cortisol) Bile Acid (cholic acid) Hydrophobic chain Only oxygen Shortened and oxidized chain α,β -unsataurated ketone or aromatic stereochemistry at C5 Carboxylic acid / ester or sulfate
Background image of page 2
Cholesterol Transport The bad reputation that is associated with the steroids is primarily due to cholesterol and the fact that it is an extremely insoluble molecule. Because of its insolubility there
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/05/2008 for the course BIOCHEM 423 taught by Professor Osgood during the Spring '08 term at New Mexico.

Page1 / 9

26 Cholesterol - Biochemistry Education BIOC 423:...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online