Cholesterol is a waxy substance made by the liver, essential for hormone production, digestion, and cell membrane integrity. It exists in two forms: LDL (bad cholesterol) which can lead to plaque buildup in arteries, and HDL (good cholesterol) that helps remove excess cholesterol from the body. Disorders related to cholesterol include hyperlipidemia (high levels) and hypolipidemia (low levels), with various causes and recommended lifestyle adjustments to manage cholesterol levels.

2. Some things are
good in
abundance, but
cholesterol isn't
one of them.
isolated in 1784
M.Saeed
M.Phil
Biochemistry
Khyber medical
university
Peshawar

3.  Cholesterol is a waxy, fat-like substance
made by the liver that's found in all the
cells in your body.
 Your body needs some cholesterol to
make hormones, vitamin D, and
substances that help you digest foods

4.  Cholesterol, exclusively found in animal.
 . lt is widely distributed in all cells and is a
major component of cell membranes and
lipoprotein.
 . Cholesterol (Creek: chole-bile) was first
isolated from bile.
 Cholesterol literally means 'solid alcohol
from bile.'

5.  The structure of cholesterol (C27H46OH).
 . lt has one hydroxyl group at C3 and a
double bond between C5 and C6.
 Cholesterol contains a total of 5 methyl
group.
 As a structural component of plasma
membranes, cholesterol is an important
determinant of membrane permeability

8.  There are two basic types of cholesterol: LDL (low-
density lipoprotein, or "bad cholesterol,") and HDL
(high-density lipoprotein, or "good cholesterol“
 Lipoproteins are made of fat and proteins.
Cholesterol moves through your body while inside
lipoproteins.

9.  HDL is known as “good cholesterol” because it
transports cholesterol to your liver to be expelled from
your body. HDL helps rid your body of excess
cholesterol so it’s less likely to end up in your arteries
 LDL is called “bad cholesterol” because it takes
cholesterol to your arteries, where it may collect in
artery walls. Too much cholesterol in your arteries may
lead to a buildup of plaque known as atherosclerosis.
This can increase the risk of blood clots in your
arteries. If a blood clot breaks away and blocks an
artery in your heart or brain, you may have
a stroke or heart attack.

12.  Cholesterol is found in association with fatty
acids to- form cholestervl esters (esterification
occurs at the OH group of C3.
 Several reactions given by cholesterol are
useful for its qualitative identification and
quantitative estimation. These include
Salkowski's test, Liebermann-Burchard
reaction and Zak's test.

13.  Cholesterol is an yellowish crystalline solid.
 The crystals, under the microscope, show a
notched (E) appearance.
 Cholesterol is insoluble in water
 soluble in organic solvents such as
chloroform, benzene, ether etc.

14.  . lt is present in abundance in nervous tissues.
 lt appears that cholesterol functions as an
insulating cover for the transmission of
electrical impulses in the nervous tissue.
 Cholesterol performs several other
biochemical functions which include its role in
membrane structure and function, in the
synthesis of bile acids, hormones (sex and
cortical) and vitamin D.

15.  Two cholesterol disorders are
hyperlipidemia, and hypolipidemia.
 Hyperlipidemia
 means you have an unusually high level
of fat (lipids) in your blood. This puts
you at risk for many health problems,
including heart attack and stroke. It is
sometimes called high blood cholesterol

16.  Hypolipidemia
 Means you have an unusually low level of fat
in your blood. It is sometimes called low
blood cholesterol.

17.  Being overweight
 Not exercising regularly
 Overuse of alcohol
 Family history. High blood cholesterol can be an
inherited condition.
 Age and sex. As you age, your LDL ("bad
cholesterol") level rises. After age 55, women have
higher LDL levels than men.
 Diseases like diabetes, hypothyroidism, Cushing's
syndrome, and kidney failure
 Medications like birth control pills, beta-blockers,
estrogen, corticosteroids, and certain diuretics

18.  Hypolipidemia can be caused by several
things:
 Hypothyroidism
 Anemia (a low amount of red blood cells)
 Malnutrition, or a lack of food
 Liver disease
 The body being unable to absorb food
(malabsorption)
 Rare genetic conditions,
 Tangier disease

20.  To reduce cholesterol in your blood:
 Follow a healthful diet, eating foods low in
total fat and saturated fat
 Maintain a healthful weight
 Exercise at least three times a week, for 30
minutes at a stretch
 Have your total cholesterol rechecked in one
to two years if:

21.  Statins lower LDL ("bad cholesterol") levels
 Bile Acid are sometimes prescribed with statins, and
help lower LDL cholesterol levels
 Nicotinic Acid lowers LDL cholesterol and
triglycerides, and raises HDL ("good" cholesterol)
levels
 Fibrates lower triglyceride levels, and may increase
HDL levels