BIO 1050 Ch 5 Lipids
In the listing of ingreidents on a food label, the presence of _________ (2) is an indiciation that a product is a source of trans fats
- Margarine - Partially-hydrogenated oil
What are some examples of foods that are cholesterol-free?
- Margarine - Vegetable oil - Peanut butter - Vegetable shortening
What are the functions of HDL cholesterol in the bloodstream?
- Picks up cholesterol from dying cells and other sources - Donates cholesterol to other lipoprotein for transport back to the liver for excretion
The type of fat most likely not to become rancid are ________ and __________ because they contain fewer carbon-carbon double bonds
- Saturated fats - Trans fats
Which three organs and/or glands produce lipase?
- Stomach - Salivary glands - Pancreas
What happens to a food product when it becomes hydrogenated?
- Trans fatty acid content is increased - The molecular shape of the fats in the food resembles saturated fats
What are some food sources of EPA and DHA?
- Tuna - Salmon - Sardines
What two chemical groups are found at the end of either side of the fatty-acid carbon chain?
- Acid group (COOH) - Methyl group (CH3)
Fat digestion is rapid and thorough in the small intestine under what "right" circumstances?
- Bile is released from the gallbladder - Lipase breaks triglycerides down to monoglycerides
What are the functions of phospholipids in the body?
- Digestion of fats - Formation of cell membranes - Absorption and transport of nutrients
Why are triglycerides ideal for fat storage?
- Energy dense - Chemically stable
What are the major functions of fatty acids and trigylycerides in the body?
- Energy storage - Insulation - Transport of fat-soluble vitamins
What are the by-products from chylomicron digestion?
- Free fatty acids - Glycerol - Chylomicron remnant
What are functions of cholesterol?
- Helps form hormones - Provide structure to cells - Building block for bile acids
Which two fatty acids are considered essential?
- Linoleic - Alpha-linolenic
As components of cell membranes, phospholipids.....
Are a source of essential fatty acids for the cell
A long-chain fatty acid is defined as a fatty acid that contains _____ or more carbon atoms in length
12
The acceptable range for lipids is _____% to ______% of kilocalories
20, 35
According to AHA, to reduce the risk for cardiovascular disease, saturated fats should contribute no more than _____ to _____ of total kilocalories
5% to 6%
How do you convert a liquid oil to a solid fat at room temperature?
Add hydrogens to the liquid fat (hydrogenation)
Lipoprotein lipase breaks down triglycerides in the ____________
Bloodstream
Why are the chemical structures of trans and saturated fatty acids similar?
Both have a straight shape
What is a common example of sterols?
Cholesterol
What is the primary component of the lipoprotein LDL?
Cholesterol
_____________ is a type of lipid that is found only in foods of animal origin
Cholesterol
Which fatty acid has the following chemical structure: hydrogens are found on the same side of the carbon-carbon double bond?
Cis
Food manufacturers use the process of hydrogenation to.....
Convert liquid oils into more solid fats
The AHA recommends using plant oils rather than animal fats in food preparation to...
Decrease saturated fat intake
What is the health effect associated with consumption of polyunsaturated fatty acids?
Decreases blood levels of cholesterol
Pressure in the arterial blood vessels when the heart is between beats
Diastolic blood pressure
Essential fatty acids must be obtained from the _____
Diet
What are some examples of foods that contain cholesterol?
Eggs, ice cream, chicken
A major function of phospholipids (e.g. lecithin) in foods is to act as a(n) ______________
Emulsifier
_________ fatty acids must be supplied by the diet, whereas ________ fatty acids can be synthesized by the body and do not need to be supplied by the diet
Essential; nonessential
T/F: Most Americans need to drastically reduce the amount of fat they consume each day
False
Fat gives food products.....
Flavor, creaminess
Risk for development of cardiovascular disease increases when _______ levels are low and ______ levels are high in the bloodstream
HDL, LDL
What is the most important functions of the phospholipid molecule?
Help form cell membranes
A teaspoon of stick margarine has ________ trans fatty acids than a teaspoon of tub margarine
More
Which fatty acid has the following chemical structure: hydrogens are found on opposite sides of the carbon-carbon double bond?
Trans
What is the health effect associated with consumption of saturated fatty acids?
Increases blood levels of cholesterol
What the final destination of glycerol in the body?
It circulates back to the liver
What is the chemical structure of an omega-6 fatty acid?
It contains the first carbon-carbon double bond on the sixth carbon from the methyl end of the carbon chain
What is the chemical structure of an omega-3 fatty acid?
It contains the first carbon-carbon double bond on the third carbon from the omega end of the carbon chain
What the final destination of chylomicron remnant in the body?
It is removed from circulation by the liver and recycled to make other lipoproteins and bile acids
________ is a phospholipid and a major component of cell membranes
Lecithin
Which enzyme plays an important role in fat digestion?
Lipase
Chylomicrons, VLDL, LDL, and HDL are classified as ______________
Lipoproteins
___________ transport lipids from the small intestine and liver to body tissues
Lipoproteins
Monounsaturated and polyunsaturated fatty acids are typically __________ at room temperature
Liquid
Oils rich in unsaturated fatty acids are typically __________ at room temperature.
Liquid
The majority of fatty acids in the body and in foods are _______-chain fatty acids
Long
What are some examples of foods that are considered high in fat?
Margarine, butter, salad oils, mayo
Sterols contain a __________ structure
Multi-ring
What is the main function of antioxidants?
Neutralize free radicals
Essential fatty acid; alpha-linolenic acid
Omega-3
Reduced triglycerides, reduced blood clotting, and reduced pain from rheumatoid arthritis are benefits associated with intake of which fatty acids?
Omega-3
Which fatty acid decreases blood clotting and inflammation?
Omega-3
Fatty fish provide eicosapentaenoic acid (EPA) and docsahexaenoic acid (DHA), which are two _______________ that are important for brain and heart health
Omega-3 fatty acids
Essential fatty acid; linoleic acid
Omega-6
Which fatty acid increases blood clotting and inflammation?
Omega-6
Nonessential fatty acid
Omega-9
Monounsaturated fatty acids have what type of carbon bond?
One double bond
The majority of fat digestion is accomplished by ________ __________
Pancreatic lipase
Liquid fat at room temperature is a _________________________ fat
Polyunsaturated
What is the primary component of the lipoprotein HDL?
Protein
____________ occurs when the double bonds in unsaturated fatty acids in food products are broken down by ultraviolet light or oxygen
Rancidity
Why is the potential for fat rancidity a problem for manufacturers?
Rancidity of fats decreases the food's shelf life
Animal fats are high in ___________ fatty acids
Saturated
Egg yolks are rich in ______________ fatty acids, but not trans fatty acids
Saturated
Which two fatty acids tend to increase LDL-cholesterol in the blood?
Saturated, trans
Saturated fatty acids have what type of carbon bond?
Single
The more saturated a fat is, the more ____________ it is at room temperature
Solid
What is the function of an emulsifier?
Suspends fats in water
Pressure in the arterial blood vessels associated with pumping of the blood from the heart
Systolic blood pressure
_________ fatty acids tend to decrease HDL-cholesterol in the blood
Trans
Compared to foods made with unprocessed plant oils, partially hydrogenated oils are less likely to go rancid because....
They have fewer double bonds
How are long-chain fatty acids absorbed?
They reform into a triglyceride in the intestinal absorptive cell and travel through the lymphatic system
How are short and medium-chain fatty acids absorbed?
They travel as a water-soluble molecule through the portal vein to the liver
The first five ingredients listed on the label for cake frosting are sugar, vegateble oil, shortening (made with partially hydrogenated soybean and cottonseed oils), water and corn syrup. This product is a rich source of ____________
Trans fatty acids
High levels of HDL in the blood tend to slow the development of cardiovascular disease because HDL......
Transports cholesterol from the bloodstream to the liver for excretion
Three fatty acids combine with glycerol to form a __________________
Triglyceride
What is the primary component of the lipoprotein Chylomicron?
Triglyceride
What is the body's most efficient form of stored energy?
Triglycerides
T/F: The hydrogenation process produces trans fats
True
T/F: The process of oxidation usually changes the shape and/or function of a substance
True
Polyunsaturated fatty acids have what type of carbon bond?
Two or more double bonds
Is an omega-3 fatty acid saturated or unsaturated?
Unsaturated
Margarine is made from plant oils which are rich in ______________ fatty acids
Unsaturated
Omega-6 fatty acids are also called ____________ fatty acids
Unsaturated
Why do reduced-fat foods contain the same, or similar, amount of calories as their reference foods?
When fat is removed, sugar is usually added to maintain a palatable flavor and texture, usually resulting in similar energy density
Can cholesterol be made by the body?
Yes
Can sterols be produced by the body?
Yes
