NTRI Chapter 5: Lipids
True or False: There is no way high-fat foods can be included in a well-balanced healthy diet.
False
What are some of the risk factors for cardiovascular disease?
Family history, smoking, hypertension, blood cholesterol > 200mg
What are some examples of foods that contain cholesterol?
Lean ground beef, eggs, turkey
What is the recommendation for trans fat intake according to the Food and Nutrition Board?
Limit intake, consume sparingly
Fat digestion is rapid and thorough in the small intestine under what "right" circumstances?
Lipase breaks down triglycerides down to monoglycerides and bile from the gallbladder is present
Name the class of nutrients that consists of triglycerides, phospholipids, and sterols.
Lipids
What enzyme breaks down triglycerides into free fatty acids and glycerol in the bloodstream?
Lipoprotein lipase
__________ transport lipids from the small intestine and liver to body tissues.
Lipoproteins
__________-density lipoprotein is considered the "bad" cholesterol.
Low
In the listing of ingredients on a food label, the presence of __________ is an indication that a product is a source of trans fats.
Margarine or partially-hydrogenated oil
The Acceptable Macronutrient Distribution Range set by the Food and Nutrition Board for lipids is __________% to __________% of kilocalories.
25; 35
You just ate a food item containing 5 grams of fat, which means that the food provides __________ kilocalories from fat.
45
The Food and Nutrition Board recommends that at least __________% of total calories come from essential fatty acids.
5
Linoleic acid is an omega-__________ fatty acid; alpha-linolenic acid is an omega-__________ fatty acid.
6; 3
What is a triglyceride?
A molecule consisting of three fatty acids bonded to a glycerol.
Why are the chemical structures of trans and saturated fatty acids similar?
Both have a straight shape
What are some components of plaque?
Calcium, cholesterol, white blood cells
What are some examples of food sources that contain cholesterol?
Eggs, Ice cream, Chicken
Identify one product of triglyceride digestion that can be absorbed into the cells lining the small intestine.
Monoglyceride
What is the main function of antioxidants?
Neutralize free radicals
According to the American Heart Association, to reduce risk for cardiovascular disease, saturated fats should contribute...
No more than 7% of total kilocalories
What is the function of an emulsifier?
Suspends fats in water
Describe the fatty acid's structure: -Saturated fatty acid -Monounsaturated fatty acid -Polyunsaturated fatty acid
Saturated fatty acid: no carbon-carbon double bond Monounsaturated fatty acid: one carbon-carbon double bond Polyunsaturated fatty acid: two or more carbon-carbon double bonds
Differentiate between types of blood pressure: -Systolic blood pressure -Diastolic blood pressure
Systolic blood pressure: pressure in the arterial blood vessels associated with pumping of the blood from the heart Diastolic blood pressure: pressure in the arterial blood vessels when the heart is between beats
What happens to a food product when it becomes hydrogenated?
The molecular shape of the fats in the food resembles saturated fats Trans fatty acid content is increased
How are the different types of fatty acids distinguished?
The position and number of carbon-carbon double bonds along the skeleton. The length of the carbon skeleton.
Why are triglycerides ideal for fat storage?
They are energy dense and they are chemically stable
Which statements are true about sterols?
They contain a multi-ring structure. They can be produced by the body. Cholesterol is a common example.
__________ fatty acids, which are a byproduct of hydrogenation of vegetable oils, are similar to saturated fatty acids in structure and physiological effects.
Trans
Which of the following is the body's most efficient form of stored energy? -Phospholipids -Triglycerides -Glycogen -Sterols
Triglycerides
True or False: HDL removes cholesterol from cells and returns to the liver for excretion.
True
True or False: Linoleic acid is an essential omega-6 fatty acid.
True
True or False: The process of oxidation usually changes the shape and/or function of a substance.
True
True or False: Monounsaturated and polyunsaturated fatty acids are typically liquid at room temperature.
True: The chemical structures of unsaturated fatty acids do not allow them to pack tightly together; thus they are liquid at room temperature
What are some examples of foods that are cholesterol-free?
Vegetable oil, vegetable shortening, peanut butter, and margarine
A long-chain fatty acid is defined as...
a fatty acid that contains 12 or more carbon atoms in length.
The main sources of saturated fat in American diets are...
animal fats
As components of cell membranes, phospholipids...
are a source of essential fatty acids for the cell.
The enzyme __________ plays an important role in fat digestion.
lipase
The gastric __________ enzyme released in the stomach acts primarily on triglycerides that have fatty acids with short-chain lengths.
lipase
A __________ is a type of lipid that contains a glycerol backbone, two fatty acids, and a phosphorus group.
phospholipid
To reduce heart attack risk, the American Heart Association recommends consuming fish...
twice per week.
An omega-3 fatty acid is...
unsaturated
List the steps of the development of atherosclerosis in the arteries starting with arterial damage and ending with a heart attack:
(1) Damage occurs in the blood vessel lining. (2) Plaque is deposited at the site of initial damage. (3) As plaque accumulates, arteries harden, narrow, and lose elasticity. (4) Clot or spasm in a plaque-clogged artery leads to a heart attack.
List the steps of dietary fat absorption in the order they occur:
(1) Glycerol, monoglycerides, and fatty acids are absorbed from the lumen of the small intestine into the small intestinal cells. (2) Triglycerides are reassembled within the cells lining the small intestine. (3) Triglycerides are packaged into chylomicrons. (4) Chylomicrons enter the lympatic system.
List the steps of fat digestion and absorption starting in the mouth and ending at the small intestine:
(1) Some lipase is released by the salivary glands and stomach (2) Salivary lipase and gastric lipase begin digesting short-chain fatty acids in the stomach (3) Bile emulsifies the fats (4) Pancreatic lipase digests long-chain fatty acids and triglycerides (5) Triglycerides are broken down and absorbed in the small intestine
Describe the bonding scheme of each polyunsaturated fatty acid: -Alpha-linolenic acid -Linolenic acid -Oleic acid
-Alpha-linolenic acid: first carbon-carbon double bond is at the third carbon from the methyl end -Linolenic acid: first carbon-carbon double bond is at the sixth carbon from the methyl end -Oleic acid: first carbon-carbon double bond is at the ninth carbon from the methyl end
Describe each type of lipid: -Cholesterol -Triglyceride -Phospholipid
-Cholesterol: waxy lipid found in all body cells -Triglyceride: major form of lipid in food and the body -Phospholipid: forms lipid bilayer of cell membrane
List the type of fat associated with the food source: -Fat in beef, pork, lamb, lard -Margarine, shortening -Corn oil, fish oil sunflower oil, safflower oil -Olive oil, canola oil, peanut oil
-Fat in beef, pork, lamb, lard: long-chain saturated fat -Margarine, shortening: trans fat -Corn oil, fish oil sunflower oil, safflower oil: polyunsaturated fat -Olive oil, canola oil, peanut oil: monounsaturated fat
When choosing fats in your diet, which guidelines are important to keep in mind?
-Fat should make up 20-35% if total kilocalories -Select more plant sources and fewer animal sources of fat.
Describe the final destinations in the body for the by-products from chylomicron: -Free fatty acids -Glycerol -Chylomicron remnant
-Free fatty acids: Absorbed by cells within the vicinity and reform into triglyceride for storage or use. -Glycerol: Circulates back to the liver -Chylomicron remnant: Removed from circulation by the liver and recycled to make other lipoproteins and bile acids.
Which of the following are functions of cholesterol? -Incorporation into cell structures -Synthesis of certain hormones -Synthesis of certain bile acids -Synthesis of certain carbohydrates
-Incorporation into cell structures -Synthesis of certain hormones -Synthesis of certain bile acids
Which of the following are types of lipoproteins? -LDL -CVD -HDL -VLDL
-LDL: low density lipoproteins transport cholesterol from the liver to body cells -HDL: high density lipoproteins pick up cholesterol from the bloodstream and transport it to the liver -VLDL: very low density lipoproteins transport triglycerides from the liver to body cells
Name the type of fat that matches the content description: -Less than 0.5g of fat per serving -At least 25% less fat per serving in comparison to the full-fat version of the food product -3g of fat or less per serving (or, if the serving size is small, per 50 grams of food)
-Less than 0.5g of fat per serving: Fat free -At least 25% less fat per serving in comparison to the full-fat version of the food product: Reduced or less fat -3g of fat or less per serving (or, if the serving size is small, per 50 grams of food): Low fat
Name the type of cholesterol that matches the content description: -No more than 2mg of cholesterol per serving -No more than 20mg of cholesterol and no more than 2g of saturated fat per serving -Contains 25% less cholesterol than the reference food and no more than 2g saturated fat per serving
-No more than 2mg of cholesterol per serving: reduced cholesterol -No more than 20mg of cholesterol and no more than 2g of saturated fat per serving: low cholesterol -Contains 25% less cholesterol than the reference food and no more than 2g saturated fat per serving: cholesterol free
Describe the correct effect on blood clotting and inflammation of each fatty acid: -Omega-3 -Omega-6
-Omega-3: decrease blood clotting and inflammation -Omega-6: increase blood clotting and inflammation
Which of the following food ingredients indicate the presence of fat in a food product? -Partially hydrogenated vegetable oil -Sucralose -Egg yolks -Shortening -Cream -Lard
-Partially hydrogenated vegetable oil -Egg yolks -Shortening -Cream -Lard
Describe the chemical structure of the lipid: -Sterol -Triglyceride
-Sterol: multi-ring structure with a hydroxyl group -Triglyceride: three fatty acids attached to a glycerol backbone
What are the major functions of fatty acids and triglycerides in the body?
-insulation -energy storage -transport of fat-soluble vitamins -building blocks for enzymes
Arrange the foods from the lowest % of kcal from fat to highest % of kcal from fat: -Baked beans -Whole milk -Canola oil -Cheddar cheese
1. Baked Beans 2. Whole Milk 3. Cheddar Cheese 4. Canola Oil
The leading cause of death among North American adults is...
Cardiovascular disease
If a food manufacturer sets out to reduce the fat content of a cookie, the food scientists will need to consider...
Changes in the texture and flavor of the food product
Which of the following are food sources high in saturated fat? -Cheeseburger -Salmon -Whole milk -Walnuts
Cheeseburger, Whole milk
__________ is a type of lipid that is found only in foods of animal origin.
Cholesterol
Explain the function of each lipoprotein: -Chylomicron -VLDL -LDL -HDL
Chylomicron: carries dietary fat from the small intestine to cells. VLDL: carries lipids made and taken up by the liver to cells. LDL: carries cholesterol made by the liver and from other sources to cells. HDL: contributes to cholesterol removal from cells and excretion from the body.
Describe the type of fatty acid corresponding to its chemical structure: -Cis fatty acid -Trans fatty acid
Cis fatty acid: Hydrogens are found on the same side of the carbon-carbon double bond Trans fatty acid: Hydrogens are found on the opposite sides of the carbon-carbon double bond
What are some health benefits associated with consuming a diet high in omega-3 fatty acids?
Decreased blood triglyceride levels Reduced risk of heart disease Management of pain resulting from rheumatoid arthritis Reduced inflammation
Which of the following are true in terms of triglyceride digestion and absorption? -Digestion primarily occurs in the stomach via gastric lipase -Digestion primarily occurs in the small intestine via pancreatic lipase -Fatty acids and monoglycerides are absorbed by the intestinal cells -One outer fatty acid is removed prior to absorption -Two outer fatty acids are removed prior to absorption
Digestion primarily occurs in the small intestine via pancreatic lipase. Two outer fatty acids are removed prior to absorption. Fatty acids and monoglycerides are absorbed by the intestinal cells.
Formed from the breakdown of triglycerides, a __________ consists of two fatty acids bound to a glycerol backbone.
Diglyceride
Lipids are a diverse group of chemical compounds. Which of the following properties do all types of lipids have in common?
Do not readily dissolve in water
Describe the chemical structure of the following types of lipids: -Fatty acid -Triglyceride -Phospholipid -Sterol
Fatty acid: chain of carbons flanked by hydrogens Triglyceride: glycerol backbone with three fatty acids Phospholipid: glycerol backbone with fatty acids and at least one phosphorus-containing group Sterol: multi-ringed compound with a hydroxyl group
What are functions of phospholipids in the body?
Formation of cell membranes, Absorption and transport of nutrients, Digestion of fats
What are the main functions of cholesterol?
Helps form hormones, building blocks for bile acid, provide structure to cells
__________-density lipoprotein is considered the "good" cholesterol.
High
Butter and margarine have about the same amount of fat, but the types of fatty acids in butter and margarine are different. Compared to margarine, butter has a __________ proportion of saturated fatty acids.
Higher; animal fats are the chief contributors of saturated fatty acids in the American diet. Margarine is made from plant oils, which are rich in unsaturated fatty acids.
__________ is the process of adding hydrogens to unsaturated fats, which makes a liquid fat more solid at room temperature.
Hydrogenation
How does meeting the recommendation for fatty fish consumption decrease the risk for heart attack?
Increased intake of omega-3 fatty acids in fatty fish reduces inflammation and the formation of blood clots
Which statements are true about a monoglyceride?
It consists of one fatty acid bonded to a glycerol backbone, and it is one of the products of digestion of triglycerides
What does it mean when a fatty acid is considered essential?
It must be supplied by the diet in order to maintain health
Which of the following are true about essential fatty acids? -Omega-3 fatty acids reduce inflammation and blood clotting -They are synthesized by the body -Omega-6 fatty acids increase inflammation and blood clotting -Omega-6 fatty acids increase inflammation but decrease blood clotting -They are unable to be synthesized by body
Omega-6 fatty acids increase inflammation and blood clotting; They are unable to be synthesized by the body; Omega-3 fatty acids reduce inflammation and blood clotting
What are some examples of foods that may contain partially hydrogenated (trans) fats?
Potato chips, stick margarine, shortening, french fries
What are some examples of foods that are considered high in fat?
Salad oils, butter, margarine, and mayonnaise.
What are some food sources of EPA and DHA?
Sardines, salmon, and tuna
Describe the fatty acid type's chemical structure: -Saturated fatty acid -Monounsaturated fatty acid -Polyunsaturated fatty acid
Saturated fatty acid: contains no carbon-carbon double bonds Monounsaturated fatty acid: one carbon-carbon double bond Polyunsaturated fatty acid: two or more carbon-carbon double bonds
A major function of phospholipids (e.g., lecithin) in foods is to act as a(n)
emulsifier
Linoleic acid and alpha-linolenic acid are both...
essential fatty acids
Compared to Whites, African-Americans have __________ risk for developing cardiovascular disease.
higher
High dietary consumption of trans fatty acids __________ the risk of cardiovascular disease.
increases
Butter is solid at room temperature. Butter contains mostly __________ fatty acids.
saturated
A compound containing a multi-ring structure and a hydroxyl group is a(n) __________.
sterol
If the label of a tub margarine product says the product is "reduced-fat," this means...
the product contains 25% less fat than regular margarine.
