{"id":237,"date":"2017-10-27T17:14:34","date_gmt":"2017-10-27T17:14:34","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/sunynutrition\/?post_type=chapter&p=237"},"modified":"2017-11-10T18:27:13","modified_gmt":"2017-11-10T18:27:13","slug":"2-37-sterols","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/atd-herkimer-nutrition\/chapter\/2-37-sterols\/","title":{"raw":"2.37 Sterols","rendered":"2.37 Sterols"},"content":{"raw":"
\r\n\r\nThe last category of lipids are the sterols. Their structure is quite different from the other lipids because sterols are made up of a number of carbon rings. The generic structure of a sterol is shown below.\r\n
\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"735\"]\"\" Figure 2.371 Generic structure of a sterol[\/caption]\r\n\r\n<\/div>\r\nThe primary sterol that we consume is cholesterol. The structure of cholesterol is shown below.\r\n
\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"440\"]\"\" Figure 2.372 The carbon ring structure of cholesterol1<\/sup>[\/caption]\r\n\r\n<\/div>\r\nCholesterol is frequently found in foods as a cholesterol ester, meaning that there is a fatty acid attached to it. The structure of a cholesterol ester is shown below.\r\n
\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"789\"]\"\" Figure 2.373 Structure of a cholesterol ester[\/caption]\r\n\r\n<\/div>\r\nAll sterols have a similar structure to cholesterol. Cholesterol is only found in foods of animal origin. If consumers were more knowledgeable, intentionally misleading practices, such as labeling a banana \u201ccholesterol free\u201d, would not be as widespread as they currently are today.\r\n\r\nFunction<\/b>\r\n\r\nAlthough cholesterol has acquired the status of a nutrition \"villain\", it is a vital component of cell membranes and is used to produce vitamin D, hormones, and bile acids. You can see the similarity between the structures of vitamin D and estradiol, one of the forms of estrogen shown below.\r\n<\/colgroup>\r\n\r\n\r\n
\r\n
\"\"<\/div><\/td>\r\n
\r\n
\"\"<\/div><\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\nFigure 2.373 Structures of vitamin D3 and estradiol (a form of estrogen)2,3<\/sup>\r\n\r\nWe do not need to consume any cholesterol from our diets (not essential) because our bodies have the ability to synthesize the required amounts. The figure below gives you an idea of the cholesterol content of a variety of foods.\r\n
\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"1106\"]\"\" Figure 2.374 The cholesterol content (mg) of foods4<\/sup>[\/caption]\r\n\r\n<\/div>\r\nThere is neither bad nor good cholesterol, despite these descriptions being commonly used for LDL and HDL, respectively. Cholesterol is cholesterol. HDL and LDL contain cholesterol but are actually lipoproteins that will be described later in chapter 4.\r\n\r\nReferences & Links<\/b>\r\n\r\n1. http:\/\/en.wikipedia.org\/wiki\/File:Cholesterol.svg\r\n\r\n2. http:\/\/en.wikipedia.org\/wiki\/File:Cholecalciferol.svg\r\n\r\n3. http:\/\/en.wikipedia.org\/wiki\/File:Estradiol2.png\r\n4. http:\/\/ndb.nal.usda.gov\/\r\n\r\n<\/div>","rendered":"
\n

The last category of lipids are the sterols. Their structure is quite different from the other lipids because sterols are made up of a number of carbon rings. The generic structure of a sterol is shown below.<\/p>\n

\n
\"\"<\/p>\n

Figure 2.371 Generic structure of a sterol<\/p>\n<\/div>\n<\/div>\n

The primary sterol that we consume is cholesterol. The structure of cholesterol is shown below.<\/p>\n

\n
\"\"<\/p>\n

Figure 2.372 The carbon ring structure of cholesterol1<\/sup><\/p>\n<\/div>\n<\/div>\n

Cholesterol is frequently found in foods as a cholesterol ester, meaning that there is a fatty acid attached to it. The structure of a cholesterol ester is shown below.<\/p>\n

\n
\"\"<\/p>\n

Figure 2.373 Structure of a cholesterol ester<\/p>\n<\/div>\n<\/div>\n

All sterols have a similar structure to cholesterol. Cholesterol is only found in foods of animal origin. If consumers were more knowledgeable, intentionally misleading practices, such as labeling a banana \u201ccholesterol free\u201d, would not be as widespread as they currently are today.<\/p>\n

Function<\/b><\/p>\n

Although cholesterol has acquired the status of a nutrition “villain”, it is a vital component of cell membranes and is used to produce vitamin D, hormones, and bile acids. You can see the similarity between the structures of vitamin D and estradiol, one of the forms of estrogen shown below.<\/p>\n\n\n\n<\/colgroup>\n\n\n
\n
\"\"<\/div>\n<\/td>\n
\n
\"\"<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Figure 2.373 Structures of vitamin D3 and estradiol (a form of estrogen)2,3<\/sup><\/p>\n

We do not need to consume any cholesterol from our diets (not essential) because our bodies have the ability to synthesize the required amounts. The figure below gives you an idea of the cholesterol content of a variety of foods.<\/p>\n

\n
\"\"<\/p>\n

Figure 2.374 The cholesterol content (mg) of foods4<\/sup><\/p>\n<\/div>\n<\/div>\n

There is neither bad nor good cholesterol, despite these descriptions being commonly used for LDL and HDL, respectively. Cholesterol is cholesterol. HDL and LDL contain cholesterol but are actually lipoproteins that will be described later in chapter 4.<\/p>\n

References & Links<\/b><\/p>\n

1. http:\/\/en.wikipedia.org\/wiki\/File:Cholesterol.svg<\/p>\n

2. http:\/\/en.wikipedia.org\/wiki\/File:Cholecalciferol.svg<\/p>\n

3. http:\/\/en.wikipedia.org\/wiki\/File:Estradiol2.png
\n4. http:\/\/ndb.nal.usda.gov\/<\/p>\n<\/div>\n\n\t\t\t

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Candela Citations<\/h3>\n\t\t\t\t\t
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