Chapter 3 Fats
Terms in this set (82)
the chemical group name for organic substances of a fatty nature; the lipids include fats, oils, waxes, and other fat related compounds such as cholesterol.
the chemical group name for fats; fats are formed from a glycerol base with one, two, or three fatty acids attached to make monoglycerides,diglycerides, and triglycerides, respectively glycerides are the principal constituents of adipose tissue, and they are found in animal and vegetable fat and oils.
the major structural components of fat
the chemical name for fats in the body or in food; three fatty acids attached to a glycerol base
the state of being filled; the state of fatty acid components being filled in all their available carbon bonds with hydrogen, thus making the fat harder and more solid at room temperature; such solid food fats are generally from animal sources.
an essential fatty acid that consists of 18 carbon atoms and 2 double bonds. The first double bond is located at the sixth carbon from the omega end, making it an omega-6 fatty acid. Found in vegetable oils.
an essential fatty acid with 18 carbon atoms and 3 double bonds. The first double bond is located at the third carbon from the omega end, making it an omega-3 fatty acid. Found in soybean, canola, and flaxseed oil.
Not a fat.
A fat-related compound called a sterol that is synthesized only in animal tissues; a normal constituent of bile and a principal constituent of gallstones; in the body, cholesterol is found in animal food sources (egg yolks, liver, kidney, and meats).
Synthesized in the liver
Linked with heart disease
Does cholesterol exist in plant foods?
No, only in animal foods and body cells.
Cholesterol is needed essential for the synthesis of
bile, sex hormones, cortisone, and vitamin D
What risks are associated with high cholesterol?
atherosclerosis which can lead to heart attacks and strokes
What can be done to lower a high cholesterol level?
-Reduce the amount of total fat, saturated fats, and cholesterol.
-Increase monounsaturated fats in the diet, lose weight, and exercise.
-Increase consumption of soluble dietary fiber.
-Medication may be prescribed in some cases.
What is the maximum daily cholesterol intake?
Daily cholesterol should not exceed 300 mg.
How many mg of cholesterol does the liver manufacture daily?
Common cholesterol medications:
All brand names are ending in -vastatin
stones of cholesterol
chemical complexes of fat and protein that serve as the major carries of lipids in the plasma; they vary in density according to the size of the fat load being carried (ex, the lower the density, the higher the fat load); the combination package with water-soluble protein makes possible the transport of non-water-soluble fatty substances in the water-based blood circulation.
a lipid with a carbohydrate attached
fat stored in the cells of adipose (fatty) tissue
an emulsifying agent produced by the liver and transported to the gallbladder for concentration and storage; it is released into the duodenum with the entry of fat to facilitate enzymatic fat digestion by acting as an emulsifier
an agent that breaks down large fat globules into smaller, uniformly distributed particles; the action is chiefly accomplished in the intestine by bile acids, which lower the surface tension of the fat particles, thereby breaking the fat into many smaller droplets and facilitating contact with the fat-digesting enzyme.
packages of free fatty acids, monoglycerides, and bile salts; the hydrophobic fat particles are found in the middle of the package, whereas the hydrophilic part faces outward and allows for the absorption of fat into intestinal mucosal cells.
a lipoprotein formed in the intestinal cell that is composed of triglycerides, cholesterol, phospholipids, and protein; chylomicrons allow for absorption of fat into the lymphatic circulatory system before entering the blood circulation.
Lipids chemical elements:
same as carbohydrates; carbon, hydrogen, and oxygen
Fats belong to a group of organic compounds called
Each gram of fat contains
Functions of fat:
-carry fat-soluble vitamins (A, D, E, K)
-supply essential fatty acids
-protect and support organs and bones
-insulate from cold
-provide satiety after meals
Short-chain fatty acids have:
Medium-chain fatty acids have:
Long-chain fatty acids have:
2 to 4 carbons
6 to 10 carbons
more than 12 carbons
Animal fat food sources:
-fatty meats and fish
Plant fat food sources:
-vegetable oils and margarine
-nuts and olives
Excessive dietary fat, especially from animal food sources, is
a negative risk factor in overall health
Decrease amount of fat in diet
low-fat skim milk
egg whites instead of yolk
Most lipids in the body are
Trans fats are unnecessary in human nutrition and pose a great number of negative health consequences related to
Commercially hydrogenated fats in margarine, snack items, fast food, and many other food products used to be high in
Cholesterol is vital to membranes; it is a precursor for some hormones, and it plays important roles in human metabolism.
The main food sources of cholesterol are
egg yolks, organ meats (liver, kidney), and other meats
In addition to carbohydrates, fat serve as
a fuel for energy production
Saturated fats are ____________ at room temperature
Unsaturated fats are _______________ at room temperature
There are many types of fat substitutes. Two of the more common examples are
Simplesse, which is made by reshaping the protein of milk whey or egg whites
Olean, which is an indigestible form of sucrose
easier to control in the diet than those that are less apparent.
Obvious fats are easy to see: butter, margarine, separate cream, salad oils and dressings, lard, shortening, fatty meats (bacon, sausage, salt pork), and the visible fat on any meats.
cheese, the cream portion of homogenized milk, nuts, seeds, olives, avocados, and lean meat.
egg yolk, salad dressings
Basically, invisible fats are those that you cannot cut out of food.
-have one place among the carbon atoms where there are fewer hydrogen atoms attached than in saturated fats
-Lower low-density lipoprotein (LDL or bad cholesterol) when they replace saturated fat in one's diet
-examples: olive oil, canola oil, avocados, cashew nuts
-recommended: 15% of total daily calories
Polyunsaturated fatty acids:
have two or more places among the carbon atoms where there are fewer hydrogen atoms attached than in saturated fats.
Omega -6 (Linoleic)
Examples of polyunsaturated fats:
cooking oils made from sunflower, safflower, sesame seeds, or from corn or soybeans; soft margarines whose major ingredient is liquid vegetable oil; and fish
Essential fatty acids:
cannot be synthesized by the body and must be obtained from the diet.
Two-families of essential fatty acids:
Omega-3 --- salmon, mackerel, sardines, anchovies - fish oil
Omega-6 --- oils, pumpkin seeds, breads, poultry, eggs, cereals
Triglyceride derivative: third fatty acid replaced by phosphate group
-partially hydrophobic, partially hydrophilic
-major constituents in cell membranes
-allows transport of fats through blood stream
Fats in foods provide:
-flavor and satisfaction
-fat substitutes are not absorbed and therefore do not provide energy or essential nutrients but many provide flavor and satisfaction
Functions of fat in the body:
-helps regulate temperature
Cell Membrane structure
-forms part of cell membrane
-helps transport nutrients across cell membranes
Food sources of fat:
Hydrogenated fats - commercial fat products raise health concerns
Food label information:
-calories from fat
-calories from saturated fat
Total cholesterol lab values should be
less than 200
The American diet is high in
excess calories are stored as fat
Animal food sources contribute to
excess cholesterol and saturated fat in the diet.
A decrease in saturated fat reduces
serum total cholesterol
Substituting monounsaturated fats for saturated fat reduces
95% of indigested fats are digested
through a complex products.
-chemical digestion of fats occur mainly in the small intestine
-NO digestion of fat occurs in the mouth (mechanical breakdown only)
-only slight digesting occurs in the stomach where gastric lipase acts on emulsified fats such as those found in cream and egg yolk.
Digestion of fat in the small intestine:
-bile from the gallbladder emulsifies the fat
-enzymes from the pancreas: the enzyme pancreatic lipase reduces the fats to fatty acids and glycerol
-enzymes from the small intestine
-absorption: the body subsequently absorbs through the villi of the small intestines
carry fat in the blood to the body cells
-In the initial stages of fat absorption, bile joins with the products of fat digestion to carry fat.
-Later, protein combines with the final products of fat digestion to form special carriers called lipoproteins.
Lipoproteins are classified according to
mobility and density
-very low density lipoproteins (VLDLs)
-low density lipoproteins (LDLs)
-high density lipoproteins (HDLs)
First lipoprotein that is identified after eating.
-Lightest in weight
-Composed of 80%-90% triglycerides
Very-Low-Density Lipoproteins (VLDLs):
Made by the liver to transport lipids throughout the body
-composed of 55%-65% triglycerides
-carry triglycerides and other lipids to all cells
As the VLDL lose triglycerides, they
pick up cholesterol from other lipoproteins in the blood and they then become LDL
Carry most of the blood cholesterol from the liver to the cells.
-composed of 45% cholesterol with few triglycerides
Elevated blood levels greater than 130 mg/dL of LDL are thought to be contributing factors in
High-Density Lipoproteins (HDLs):
Carry cholesterol from the cells to the liver for eventual excretion.
-Exercise, maintaining a desirable weight, and giving up smoking are all ways to increase one's HDL
Levels of HDL greater than 40 mg/dL are thought to reduce the risk of
Healthy Diet Guidelines:
-stress the benefits of a diet low in fat, saturated fat, and cholesterol
-recommend that the fat content should not exceed 15%-25% of total kilocalories
-less than 10% of kilocalories should be from saturated fat
-dietary cholesterol should be limited to 300 mg/day
-use only lean cuts of all meats; use more poultry and seafood
-limit eggs to two or three per week
Dietary Reference Intake of Linoleic acid:
17 g/day for men
12 g/day for women
Dietary Reference Intake of Linolenic acid:
1.6 g/day for men
1.1 g/day for women
The liver controls
fat metabolism, which occurs in the cells.
-fatty acids are broken down to carbon dioxide and water, releasing energy
-fat not needed for immediate use is stored as adipose tissue
Carbon dioxide and water are waste products removed from the body by
the circulatory, respiratory, and excretory systems
-made from carbohydrates and fat
-FDA approved for use in snacks
-Government requires that food labels indicate olestra "inhibits absorption of some vitamins and other nutrients"
-should be used in moderation
-contains no calories; can cause cramps and diarrhea
-made from egg white or milk product
-can be used only in cold foods
-carbohydrate-based; derived from oat fiber
-can be used in baking but not frying
Facts about fats:
-Fat is an essential body nutrient.
-Serves as backup storage fuel for carbs
-supplies structural material for cell walls, protective padding for vital organs, insulation to maintain body temperature, and covering for nerve cells
-classes of fat include lipids, triglycerides, fatty acids, and lipoproteins
-cholesterol is a sterol that is vital in human metabolism
Myelin sheath is made of
-myelin sheath speeds the impulses
Essential fatty acids are necessary to:
-aid in tissue strength
Fatty acids and glycerides are incorporated into chylomicrons absorbed via
the lymphatic system into the bloodstream