How cholesterol formed in our body when eating Fat?

Question

Please explain how does it happen

1 saturated fat
2 trans fat
3 mono unsaturated fat
4 poly unsaturated fat

thx

Answer 1

It may surprise you to know that our bodies make all the cholesterol we need. When your doctor takes a blood test to measure your cholesterol level, the doctor is actually measuring the amount of circulating cholesterol in your blood, or your blood cholesterol level. About 85 percent of your blood cholesterol level is endogenous, which means it is produced by your body. The other 15 percent or so comes from an external source -- your diet. Your dietary cholesterol originates from meat, poultry, fish, seafood and dairy products. It's possible for some people to eat foods high in cholesterol and still have low blood cholesterol levels. Likewise, it's possible to eat foods low in cholesterol and have a high blood cholesterol level.
So, why is there so much talk about cholesterol in our diet? It's because the level of cholesterol already present in your blood can be increased by high consumption of cholesterol and saturated fat in your diet. This increase in dietary cholesterol has been associated with atherosclerosis, the build-up of plaques that can narrow or block blood vessels. (Think about what happens to your kitchen drain pipes when you pour chicken fat down the sink.) If the coronary arteries of the heart become blocked, a heart attack can occur. The blocked artery can also develop rough edges. This can cause plaques to break off and travel, obstructing blood vessels elsewhere in the body. A blocked blood vessel in the brain can trigger a stroke.

Answer 2

It is formed in your liver ! Liver secrets BILE for fat digestion and in this cholesterol also formed ! Gall stone is a cholesterol's stone ! Cholesterol crystal is beautiful one as a cube having one corner cut in cube shape !! so cube having a cut of cube on one corner !!this helps in fat digestion and it is formed in LIVER with the bile !It also formed via metabolism of the sugar called neo glucogenesis and gluconeogenesis !Our Liver is a chemicla factory in that sense ! Cholesterol is essential for healthy life !!Practically each cell of your body contains cholesterol and more specifically cell wall is mainly made of it ! Cardiac doctor have become more aggressive for this cholesterol and many pharmaceutical companies are making propaganda for to sell their products !Actually everything in excess is harmful ! Maintain your body weight and keep it flexible that's all you have to o ! Always YouRsmE

Answer 3

nerves are the blood carriers of our body.cappilaries are fine structures the connect veins and arteries.when blood flows through capplilaries the fluid part of the blood seeps into the inter cellular spaces in the cappilaries.lymph vessels carry this tissue fluid back to the blood.when you eat food containing fat they block the eassy passage of tissue fluid through the lymph vessels causing strokes.

Answer 4

1. Stage one is the synthesis of isopentenyl pyrophosphate, an activated isoprene unit that is the key building block of cholesterol.

2. Stage two is the condensation of six molecules of isopentenyl pyrophosphate to form squalene.

3. In stage three, squalene cyclizes in an astounding reaction and the tetracyclic product is subsequently converted into cholesterol.

26.2.1. The Synthesis of Mevalonate, Which Is Activated as Isopentenyl Pyrophosphate, Initiates the Synthesis of Cholesterol

The first stage in the synthesis of cholesterol is the formation of isopentenyl pyrophosphate from acetyl CoA. This set of reactions, which takes place in the cytosol, starts with the formation of 3-hydroxy-3-methylglutaryl CoA (HMG CoA) from acetyl CoA and acetoacetyl CoA. This intermediate is reduced to mevalonate for the synthesis of cholesterol (Figure 26.7). Recall that mitochondrial 3-hydroxy-3-methylglutaryl CoA is processed to form ketone bodies (Section 22.3.5).

The synthesis of mevalonate is the committed step in cholesterol formation. The enzyme catalyzing this irreversible step, 3-hydroxy-3-methylglutaryl CoA reductase (HMG-CoA reductase), is an important control site in cholesterol biosynthesis, as will be discussed shortly.

HMG-CoA reductase is an integral membrane protein in the endoplasmic reticulum.

Mevalonate is converted into 3-isopentenyl pyrophosphate in three consecutive reactions requiring ATP (Figure 26.8). Decarboxylation yields isopentenyl pyrophosphate, an activated isoprene unit that is a key building block for many important biomolecules throughout the kingdoms of life. We will return to a discussion of this molecule later in the chapter.top link
26.2.2. Squalene (C30) Is Synthesized from Six Molecules of Isopentenyl Pyrophosphate (C5)

Squalene is synthesized from isopentenyl pyrophosphate by the reaction sequence

This stage in the synthesis of cholesterol starts with the isomerization of isopentenyl pyrophosphate to dimethylallyl pyrophosphate.

These isomeric C5 units condense to form a C10 compound: isopentenyl pyrophosphate attacks an allylic carbonium ion formed from dimethylallyl pyrophosphate to yield geranyl pyrophosphate (Figure 26.9). The same kind of reaction takes place again: geranyl pyrophosphate is converted into an allylic carbonium ion, which is attacked by isopentenyl pyrophosphate. The resulting C15 compound is called farnesyl pyrophosphate. The same enzyme, geranyl transferase, catalyzes each of these condensations.

The last step in the synthesis of squalene is a reductive tail-to-tail condensation of two molecules of farnesyl pyrophosphate catalyzed by the endoplasmic reticulum enzyme squalene synthase.

The reactions leading from C5 units to squalene, a C30 isoprenoid, are summarized in Figure 26.10.top link
26.2.3. Squalene Cyclizes to Form Cholesterol

The final stage of cholesterol biosynthesis starts with the cyclization of squalene (Figure 26.11). Squalene is first activated by conversion into squalene epoxide (2,3-oxidosqualene) in a reaction that uses O2 and NADPH. Squalene epoxide is then cyclized to lanosterol by oxidosqualene cyclase (Figure 26.12). This remarkable transformation proceeds in a concerted fashion. The enzyme holds squalene epoxide in an appropriate conformation and initiates the reaction by protonating the epoxide oxygen. The carbocation formed spontaneously rearranges to produce lanosterol. Lanosterol is converted into cholesterol in a multistep process by the removal of three methyl groups, the reduction of one double bond by NADPH, and the migration of the other double bond (Figure 26.13).top link

© 2002 by W. H. Freeman and Company.

Answer 5

Please go to the follow link for molecular biology of cholestrol:
http://lib.bioinfo.pl/meid:16149