File Lipids-Chap 13
Transcript File Lipids-Chap 13
-structure of fats
-saponification and soap
-insoluble in water
(hydrophobic nature) due to non-polar
-burning of fats gives us more
energy/molecule than carbohydrates
(9/4kcal./gr.)but not as good for our
-4 groups: 1. fats and waxes; 2. complex
lipids 3. steroids; 4. prostaglandins and
Food and Calories
How many calories do you need?
• The Easy Way
If all of those calculations seem too confusing or tedious, you can
roughly estimate your daily calorie requirements using this simple
• For sedentary people: Weight x 14 = estimated cal/day
• For moderately active people: Weight x 17 = estimated cal/day
• For active people: Weight x 20 = estimated cal/day
• 3500 calories = 1 lb. Fat storage
– Animal fats are either saturated or unsaturated, but most
• Unsaturated fats are believed to lower cholesterol
levels in humans.
• Saturated fats and cholesterol are thought to contribute
to hardening of the arteries.
– Fats are stored in adipose tissue which has an insulating
function, a padding (protective) function, as well as a
• The triglyceride
structure of fats and
oils. Note the glycerol
structure on the left
and the ester structure
on the right. Also
notice that R1, R2,
and R3 are longchained molecules of
12, 14, 16, 18, 20, 22,
or 24 carbons that
might be saturated or
alcohol part = glycerol
-almost all straight-chain carboxylic acids
-10-20 carbons in length
-even number of carbons
-single/double bond dictates amount of
saturation of fat.
solid room temp.
liquid room temp.
1. pure fats and oils are colorless, odorless, and
tasteless. These properties are due to substances
dissolved in fats.
2. most fat sources have both sat. and unsat.
(see table from text.)
% of Saturated/Polyunsaturated
– APPROXIMATE AMOUNTS OF SATURATED AND POLYUNSATURATED FAT
IN DIFFERENT VEGETABLE OILS
TYPE OF OIL
SATURATED FAT POLYUNSATURATED FAT
(grams per 100 grams of oil)
Soy bean oil
Saturated vs. Unsaturated Fats
Food Label Example
Basic Fat Type Definitions
Saturated fats: These are the biggest dietary cause of high LDL levels
("bad cholesterol"). When looking at a food label, pay very close
attention to the % of saturated fat and avoid or limit any foods that are
high (for example, over 20% saturated fat). Saturated fats are found in
animal products such as butter, cheese, whole milk, ice cream, cream,
and fatty meats. They are also found in some vegetable oils -- coconut,
palm, and palm kernel oils. (Note: most other vegetable oils contain
unsaturated fat and are healthy.)
Unsaturated fats: Fats that help to lower blood cholesterol if used in
place of saturated fats. However, unsaturated fats have a lot of calories,
so you still need to limit them. There are two types: mono-unsaturated
and polyunsaturated. Most (but not all!) liquid vegetable oils are
unsaturated. (The exceptions include coconut, palm, and palm kernel
Mono-unsaturated fats: Fats that help to lower blood cholesterol if
used in place of saturated fats. However, mono-unsaturated fats have a
lot of calories, so you still need to limit them. Examples include olive
and canola oils.
Polyunsaturated fats: Fats that help to lower blood cholesterol if used
in place of saturated fats. However, polyunsaturated fats have a lot of
calories, so you still need to limit them. Examples include safflower,
sunflower, corn, and soybean oils.
Fat Type Definitions
Trans fatty acids: These fats form when vegetable oil hardens (a
process called hydrogenation) and can raise LDL levels. They
can also lower HDL levels ("good cholesterol"). Trans-fatty
acids are found in fried foods, commercial baked goods (donuts,
cookies, crackers), processed foods, and margarines.
Hydrogenated: refers to oils that have become hardened (such
as hard butter and margarine). Foods made with hydrogenated
oils should be avoided because they contain high levels of trans
fatty acids, which are linked to heart disease. (Look at the
ingredients in the food label.) The terms "hydrogenated" and
"saturated" are related; an oil becomes saturated when hydrogen
is added (i.e., becomes hydrogenated).
Partially hydrogenated: Refers to oils that have become
partially hardened. Foods made with partially hydrogenated oils
should be avoided because they contain high levels of trans fatty
acids, which are linked to heart disease. (Look at the ingredients
in the food label.)
Polyunsaturated fats are usually liquid at room temperature. Polyunsaturated fats are found in vegetable
oils such as corn oil, safflower oil, soybean oil, and sunflower oil. Polyunsaturated fats are also present in
fish and fish oils, which help to decrease triglyceride levels. Polyunsaturated fats lower LDL cholesterol
and total cholesterol but they also lower HDL cholesterol (remember HDL cholesterol is the good stuff).
Therefore, this fat should be limited to a certain degree. Too much of any of these fats will increase
dietary fat intake, and excess body fat may increase cholesterol levels and the potential to increase body
Saturated fats are usually solid or almost solid at room temperature. All animal fats, such as those in
meat, poultry, and dairy products are saturated. Processed and fast foods are also saturated. Vegetable
oils also can be saturated. Palm, palm kernel and coconut oils are saturated vegetable oils. (Fats
containing mostly unsaturated fat can be made more saturated through a process called "hydrogenation."
See the definition for hydrogenated/partially hydrogenated.")
Saturated fats are the very unhealthy fats. They make the body produce more cholesterol, which may
raise blood cholesterol levels. Excess saturated fat is related to an increased risk of cardiovascular
disease. The amount of cholesterol found in foods is not as important as the amount of saturated fat. Of
all the fats, saturated fat is the most potent determinant of blood cholesterol levels. Saturated fats
stimulates the production of LDL cholesterol ("bad" cholesterol) and therefore increases blood cholesterol
levels and the risk of heart disease. Saturated fats raise cholesterol levels and LDL-cholesterol levels
more than dietary cholesterol itself.
These fats are called hydrogenated fats. These are fats that are created when oils are "partially
hydrogenated" The process of hydrogenation changes the chemical structure of unsaturated fats by
adding hydrogen atoms to make the fats more saturated. Hydrogenation is what turns liquid oil into stick
margarine or shortening. Manufacturers use this process to increase product stability and shelf life. Thus,
a larger quantity can be produced at one time, saving the manufacturer money. Unfortunately, this moneysaving process is what contributes to elevated blood cholesterol levels and increases heart disease risk.
What are the health effects
of trans fats?
Concerns have been raised for several decades that consumption of
trans fatty acids might have contributed to the 20th century epidemic of
coronary heart disease.2
Metabolic studies have shown that trans fats have adverse effects on
blood lipid levels--increasing LDL ("bad") cholesterol while decreasing
HDL ("good") cholesterol. This combined effect on the ratio of LDL to
HDL cholesterol is double that of saturated fatty acids.3
Trans fats have also been associated with an increased risk of coronary
heart disease in epidemiologic studies.4
Based on the available metabolic studies, we estimated in a 1994
report that approximately 30,000 premature coronary heart disease
deaths annually could be attributable to consumption of trans fatty
Trans Fatty Acids
• Trans unsaturated fatty acids, or trans fats, are
solid fats produced artificially by heating liquid
vegetable oils in the presence of metal catalysts
and hydrogen.1 This process, partial
hydrogenation, causes carbon atoms to bond in a
straight configuration and remain in a solid state at
room temperature. Naturally-occurring
unsaturated fatty acids have carbon atoms that line
up in a bent shape, resulting in a liquid state at
Cholesterol and Fats
Cholesterol is a waxy, fat-like substance found in the bloodstream. It
comes from two sources- your body and food. It is made by the liver
and is used by the body to make hormones and other materials.
Cholesterol is an essential part of the human body. It must be present
for the body to function normally. However, the average high-fat/highcholesterol diet tends to add too much cholesterol to the bloodstream.
The excess cholesterol accumulates, along with other substances, in
the walls of the blood vessels. Over time, this causes the arteries to
become narrow and eventually cuts off the blood flow to the heart
leading to a heart attack, or cuts off the blood flow to the brain leading
to a stroke. Blood cholesterol is measured in milligrams per deciliter
(mg/dl). The National Cholesterol Education Program (NCEP) has set
guidelines for classifying blood cholesterol levels. They advise that a
total cholesterol level less than 200mg/dl is a desirable level for adults.
LDL and HDL
In the blood, cholesterol attaches to protein molecules of different densities to
be carried through the blood vessels by special types of proteins, called
lipoproteins. The amounts and types of lipoproteins are an important indicator
of your heart disease risk.
Low-density lipoprotein, LDL, is commonly termed "bad" cholesterol,
because an excess of cholesterol carried by them can lead to the build
up of plaque in the arteries. High LDL levels (above 160mg/dl) increase
heart disease risk because they keep cholesterol in blood circulation and
carry it to the arteries to be deposited. Excess body fat and a diet high in
saturated fat tend to increase LDL levels. LDLs are not found in food,
only in the body.
High-density cholesterol, HDL, is considered "good" or protective
cholesterol, because they carry cholesterol away from the arteries to the
liver to be excreted from the body. Individuals with high HDL levels
(above 35mg/dl) have a lower risk of heart disease. Regular exercise
helps to increase HDL levels. HDLs are not found in food, only in the
Cholesterol website info.
• Body mass index
Drugs used to decrease Cholesterol
What is Lipitor?
Lipitor is a prescription drug for lowering cholesterol. For people with high cholesterol,
Lipitor, in combination with diet, can reduce cholesterol and triglyceride levels
In medical studies of people with high cholesterol, Lipitor tablets, taken once a day, had
the following effects at doses of 10 mg to 80 mg:
Lowered total cholesterol levels by 29% to 45% (average effect depending on dose)
Lowered LDL "bad" cholesterol levels by 39% to 60% (average effect depending on
Lowered triglyceride levels by 19% to 37% (average effect depending on dose)
Increased HDL "good" cholesterol levels by 5% to 9% (average effect depending on
How does Lipitor Work?
Lipitor lowers cholesterol by blocking an enzyme in the liver that your body uses to
make cholesterol. When less cholesterol is produced, the liver takes up more of it from
the bloodstream. This results in lower levels circulating in your blood.
Olestra is a no-fat cooking oil that replaces fat in preparing foods. Olestra is made by
chemically combining sugar with the fatty acids obtained from vegetable oils. Olestra is
marketed under the brand name Olean.® Though Proctor and Gamble had been working on
the formula since 1968, it wasn't put on the market until 1996. Olestra can be used in deepfrying, and it tastes about the same as fat without the absorption of fat or calories.
There are some drawbacks, however. Some people who've eaten foods prepared with Olestra
have reported suffering from severe gas pains and diarrhea. In addition, studies have
indicated that Olestra interferes with absorption of fat-soluble vitamins A, D, E and K.
Therefore, the makers of products containing Olestra often supplement the food by adding
those particular vitamins. This is of special concern to people on the blood-thinning
medication Coumadin, as too much vitamin K counteracts the benefit of the medication.
Olestra reportedly flushes carotenoids from the body as well. Carotenoids are the plant
pigments that make fruits and vegetables red, yellow or orange, and they're also found in
green leafy vegetables. Research shows that carotenoids protect the body against diseases
such as cancer, heart disease and macular degeneration, a form of blindness.
Olestra critics have attacked the Food and Drug Administration for approving a product that
may not a hundred percent safe for the general public, and they allege that food industry
lobbyists were instrumental getting Olestra approved.
We are a diet-conscious society, but we love our fatty foods. The birth of Olestra seemed
almost too good to be true. Some may find it to be a dream come true, while others may see
it as a wolf in sheep's clothing. One manufacturer contends that Olestra is a substitute for
fat--not a substitute for common sense. It claims that like most foods, Olestra is fine if eaten
-hydrophobic tails inside of membrane and
hydophilic heads point toward intracellular and
-cholesterol embedded in membrane
-high molecular weights
-protective coatings for
plants (covering of
leaves) and animals
(feathers of birds)
-"water off of a duck“
-waxing your car
-wax in your ears
Worker bees–which live about five weeks in the summer–make wax from
about the 10th day of their lives to the 16th. When workers are roughly
10 days old, they develop special wax-producing glands in their
abdomens. They eat lots of honey. The glands convert the sugar in the
honey into wax, which seeps through small pores in the bee's body
leaving tiny white flakes on its abdomen. These bits of wax are then
chewed by the bees. The chewed wax is added to the construction of the
honeycomb. The cluster of bees means the hive temperature stays at
around 35 degrees Celsius, which keeps the wax at just the right
consistency–it's not too hot to be drippy and not too cold to be brittle.
Bees and Wax
-Fat + NaOH = soap
-if vegetable fat, softer soap
-hydrophobic portion dissolves dirt (if dirt non-soluble in water) and
hydrophilic portion attaches to water to be washed away
-in hard water (Mg and Ca), minerals will precipitate out to leave "ring"
-detergents will not allow precipitation of minerals
HOW SOAPS AND DETERGENTS
These types of energy interact and should be in proper balance. Let's
look at how they work together.
Let's assume we have oily, greasy soil on clothing. Water alone will not
remove this soil. One important reason is that oil and grease present in
soil repel the water molecules.
Now let's add soap or detergent. The surfactant's water-hating end is
repelled by water but attracted to the oil in the soil. At the same time,
the water-loving end is attracted to the water molecules.
These opposing forces loosen the soil and suspend it in the water.
Warm or hot water helps dissolve grease and oil in soil. Washing
machine agitation or hand rubbing helps pull the soil free.
Soap and Detergents
What are “performanceenhancement” steroids?
Anabolic-androgenic steroids are man-made substances related to
male sex hormones. “Anabolic” refers to muscle-building, and
“androgenic” refers to increased masculine characteristics. “Steroids”
refers to the class of drugs. These drugs are available legally only by
prescription, to treat conditions that occur when the body produces
abnormally low amounts of testosterone, such as delayed puberty and
some types of impotence. They are also prescribed to treat body
wasting in patients with AIDS and other diseases that result in loss of
lean muscle mass. Abuse of anabolic steroids, however, can lead to
serious health problems, some irreversible.
Today, athletes and others abuse anabolic steroids to enhance
performance and also to improve physical appearance. Anabolic
steroids are taken orally or injected, typically in cycles of weeks or
months (referred to as “cycling”), rather than continuously. Cycling
involves taking multiple doses of steroids over a specific period of
time, stopping for a period, and starting again. In addition, users
often combine several different types of steroids to maximize their
effectiveness while minimizing negative effects (referred to as
-can build-up due to high intake of
-essential for human body
-LDL, HDL transport it around body
-builds up uterine lining.
-peaks after ovulation of female reproductive cycle
-found in birth control pill
-see graph of reproductive cycle
-primary hormones for
male and female
-glucocorticoid: increase glucose level to
promote energy in emergency situations
-relate to "fight or flight" situations.
-anti-inflammatory effects (cortisone
injections for athletes with joint injuries)
-injections for: allergic reactions
(bronchiole tube dilation and rashes if
Signs of Ovulation
Birth Control and Cancer Risks
• There is evidence of an increased risk of breast cancer for
women under age 35 who are recent users of OCs (see
section on Breast Cancer). Studies have consistently shown
that using OCs reduces the risk of ovarian cancer (see
section on Ovarian and Endometrial Cancers). There is
evidence that long-term use of OCs may increase the risk
of cancer of the cervix (see section on Cancer of the
Cervix). There is some evidence that OCs may increase the
risk of certain cancerous liver tumors (see section on Liver