Flashcards in Chapter Five Deck (79):
What is a lipid?
A group of organic molecules, most of which do not dissolve in water. They include fatty acids, triglycerides, phospholipids, and sterols.
What do lipids contribute to food? (3)
They contribute to the texture, flavour, and aroma.
What is the AMDR recommendation for fat?
20-35% of kcals from fat.
True or False: Soluble Fibre can lower total (and unhealthy) LDL cholesterol levels.
True. The soluble fibre psyllium can also lower total and LDL cholesterol levels without lowering HDL levels.
True or False: Flaxseed can lower LDL cholesterol, but also lowers HDL.
False, Flaxseed can lower LDL without lowering HDL.
Does Soy Protein have an affect on HDL levels?
While lowering LDL, it can have no effect or raise HDL levels.
Plant Sterols and Stanols resemble what and how do they affect blood cholesterol levels?
They resemble cholesterol chemically, making it difficult for the digestive system to tell them apart and causing cholesterol absorption to lower.
What are Triglycerides?
The major form of lipid in food and in the body, they consist of three fatty acids attached to a glycerol molecule. The fatty acids determine the physical properties and health effects of the triglyceride.
What are Fatty Acids?
Organic molecules made up of a chain of carbons linked to hydrogen atoms with an acid group at one end.
What are Phospholipids?
Types of lipids containing phosphorous, the most common type are phosphoglycerides, which are composed to two fatty acids and a phosphate group attached to a glycerol molecule.
What are Sterols?
Types of lipids with a structure composed of chemical rings.
What acid group is at the end of the fatty acid chain?
What is the CH3 end of a fatty acid called?
The omega or methyl end.
What are short chain fatty acids?
Fatty acids with 4-7 carbons, they remain liquid at colder temperatures.
What are medium length fatty acids?
Range from 8-12 carbons and solidify in the fridge but become liquid at room temperature.
What are long chain fatty acids?
Greater than 12 carbons, are usually solid at room temperature and have melting points of 50 - 70 degrees Celsius.
Define Saturated Fatty Acid
A fatty acid in which all the carbon are bound to as many hydrogens as possible, with no carbon double bonds.
What are Tropical Oils?
A term used in the popular press to refer to the saturated oils (coconut, palm, and palm kernel oil) that are derived from plants that grow in tropical regions. They are more resistant to rancidity and have longer shelf lives.
What is the carbon description of palmitic acid?
What is the carbon description of stearic acid?
What are Unsaturated Fats?
Fatty acids that contain carbons not saturated with hydrogens. They melt at cooler temperatures than their saturated counterparts.
What is a Monounsaturated Fatty Acid?
A fatty acid that contains 1 carbon-carbon double bond. The most popular kind is oleic acid, found in olive and canola oils.
What is a Polyunsaturated Fatty Acid?
A fatty acid containing two or more carbon-carbon double bonds. The most common kind is linoleic acid, found in corn, safflower, and soybean oils.
What is an omega-3 Fatty Acid?
A fatty acid containing a double bond between the third and fourth carbon from the omega end.
What are three examples of omega-3 fatty acids?
1 . alpha-linolenic acid (vegetable oils)2. eicosapentaenoic acid (EPA) (fish oils)3. docosahexaenoic acid (DHA) (fish oils)
What are omega-6 Fatty Acids?
A fatty acid containing the carbon-carbon bond between the sixth and the seventh carbon from the omega end.
What are two examples of omega-6 fatty acids?
1. Linoleic acid (con and safflower oil)2. Arachidonic acid (meat and fish)
What are Trans Fatty Acids?
An unsaturated fatty acid in which the hydrogen atoms are in opposite sides of the double bond. They have higher melting points than their cis counterparts.
What are Cis Fatty Acids?
An unsaturated fatty acid with the hydrogen atoms are on the same side of the double bonds, they are more common in nature than trans fatty acids.
What is Hydrogenation?
The process whereby hydrogen atoms are added to the carbon-carbon double bonds of unsaturated fatty acids, making them more saturated. Hydrogenation bubbles hydrogen gas into liquid oil. The resulting (more saturated) fat has increased stability against rancidity and higher melting points, however only some of the bonds will become saturated and making the resulting product have more trans bonds than before.
What happens to the body when trans fats are consumed in the diet?
It raises blood cholesterol levels and increases the risk of heart attacks.
Which end of the Phosphoglyceride is soluble in fat and which end is water soluble?
The fatty acid side is soluble in fat [fat soluble tail] and the phosphate group side is soluble in water [water-soluble head].
What are Emulsifiers?
Substances that allow water and fat to mix by breaking large fat goblets into smaller ones.
What is the Lipid Bilayer?
Two layers of phophoglyceride molecules oriented so that the fat soluble fatty acid tails are sandwiched between the water soluble phosphate containing head, allowing it to control what goes into and out of the cell.
What is Lecithin?
A phosphoglyceride composed of a glycerol backbone, two fatty acids, a phosphate group, and a molecule of choline. It is a major constituent of cell membranes and is required for optimal function. Used to keep oil separating from other ingredients.
What is Cholesterol?
A lipid that is made out of multiple chemical rings and in made only by animal cells. Do not dissolve well in water, and is not necessary in the diet.
Where is 90% of cholesterol found in the body?
In cell membranes.
What is Cholesterol need for?
To synthesize vitamin D, synthesize cholic acid (a component of bile), and some hormones (such as testosterone and estrogen and cortisol [promotes glucose synthesis])
What are micelles?
Particles formed in the small intestine when the products of fat digestion are surrounded by bile acids. They facilitate the absorption of fat.
Where does most of the digestion of dietary fat take place?
In the small intestine due to the action of lipid digesting enzymes lipases.
What are Lipoproteins?
Particles containing a core of triglycerides and cholesterol surrounded by a shell of protein, phospholipids, and cholesterol that have transport proteins in blood and lymph. They help transport dietary triglycerides, cholesterol, and fat-soluble vitamins from the small intestine and store or newly synthesized lipids from the liver.
What is the Post-Prandial State?
The time following a meal where nutrients from the meal are being absorbed.
What are Chylomicrons?
Lipoproteins that transport lipids from the mucosal cells of the small intestine and deliver triglycerides to other body cells. They are transferred into the lymphatic system and then into the bloodstream without passing through the liver.
What is Lipoprotein Lipase?
An enzyme that breaks down triglycerides into fatty acids and glycerol, attached to the cell membrane of cells that line the blood vessels. The fatty acids can either be used as fuel or resynthesized into triglycerides for storage. The remains of the chylomicron go to the liver where they are disassembled.
What are VLDLs?
Very low density lipoproteins, triglycerides are in the liver are incorporated into these. Lipoproteins assembled by the liver that carry lipids from the liver and deliver triglycerides to body cells.
What are LDLs?
Low density lipoproteins, lipoproteins that transport cholesterol to cells. Elevated LDL cholesterol increases the risk of cardiovascular disease. They contain less triglycerides than VLDLS.
What is Apoprotein B (apo B)?
A protein on the surface of LDLs that must bind to a receptor protein on the cell membrane called an LDL receptor.
What is a LDL Receptor?
A protein on the surface of cells that binds to LDL particles and allows their contents to be taken up for use by the cell.
What are HDLs?
High-density lipoproteins that pick up cholesterol from cells and transport it to the liver so that it can be eliminated from the body. A high level of HDL decreases the risk of cardiovascular disease.
What functions do Lipids have after being delivered to cells? (3)
1. Used to make structural and regulatory molecules2. Stored as an energy reserve3. Broken down via cellular respiration to produce CO2, H2O, and energy in the form of ATP.
What is Adipose Tissue?
Tissue found under the skin and around body organs that is composed of fat-storing molecules. They provide insulation.
What are the two Essential Fatty Acids?
Alpha-linoleic acid (omega-3) and linolenic acid (omega-6).
What is Omega-6 important for? (4)
Growth, skin integrity, fertility, and maintaining red blood cell structure.
What are EPA and DHA synthesized from?
What are Eicosanoids?
Regulatory molecules, including prostagladins and related compounds, that can be synthesized from omega 3 and omega 6 fatty acids.
What do the Eicosanoids do from Omega-6?
Promote inflammation and promote blood clotting.
What do the Eicosanoids do from Omega-3?
Suppress inflammation and suppress blood clotting.
What ratio of Linoleic to Alpha-Linolenic Acid is preferable?
Define Cardiovascular Disease
Any disease affecting the heart and blood vessels.
What is Essential Fatty Acid Deficiency?
A condition that results in dry, scaly skin, liver abnormalities, poor healing, impaired vision and hearing, and poor growth that results when the diet does not supply enough essential fatty acids.
What is Atherosclerosis?
A type of cardiovascular disease that involves the buildup of fatty material in the artery walls.
What is Atherosclerotic Plaque?
The cholesterol-rich material that is deposited in the arteries of individuals with atherosclerosis. It consists of cholesterol, smooth-muscle cells, fibrous tissue, and eventually calcium.
What is Oxidized LDL Cholesterol?
A substance formed when the cholesterol in LDL particles is oxidized by reactive oxygen molecules. It is key in the development of atherosclerosis because it contributes to the inflammatory process.
What are Scavenger Receptors?
Proteins on the surface of macrophages that bind to oxidized LDL cholesterol and allow it to be taken up be the cell.
Seven Steps to a Heart Attack.
1. Notmal Artery2. Fatty Streak Formation3. Oxidized LDL causes white blood cells to stick4. Plaque Accumulation5. Fibrous Cap Formation6. Fibrous Cap Rupture 7. Heart Attack
What are risk factors for Heart Disease? (4)
1. High blood pressure2. Diabetes3. Obesity 4. High LDL levels
True or False: Excessive intake of cholesterol, saturated fat, and trans fatty acids can increase the risk of cardiovascular disease.
What Metabolic Effect and Observed Effect on Lipoproteins in Blood do Saturated Fatty Acids have?
Decreases LDL receptors, increases LDL cholesterol.
What Metabolic Effect and Observed Effect on Lipoproteins in Blood do Trans Fatty Acids have?
Increases cholesterol synthesis, increases LDL cholesterol and decreases HDL cholesterol.
What Metabolic Effect and Observed Effect on Lipoproteins in Blood do Cis-Polyunsaturated Fatty Acids have?
Decreases LDL cholesterol.
What Metabolic Effect and Observed Effect on Lipoproteins in Blood do Omega-6 Fatty Acids have?
Increases LDL receptor, increases bile acid synthesis, decreases LDL cholesterol, and decreases HDL cholesterol.
What Metabolic Effect and Observed Effect on Lipoproteins in Blood do Omega-3 Fatty Acids have?
Fatty acid oxidation, decreases VLDL synthesis, increases VLDL uptake, decreases VLDL levels, decreases LDL cholesterol.
What Metabolic Effect and Observed Effect on Lipoproteins in Blood do Monounsaturated Fatty Acids have?
Decreases LDL oxidation and decreases LDL cholesterol.
True or False: High fat meals can contribute to overeating because they are less satiating than energy from carbohydrates.
What does Fat-free mean?
Contains less than 0.5 g of fat per serving.
What does Low-fat mean?
Contains 3 g or less of fat per serving.
What does Reduced or Less Fat mean?
Contains at least 25% less fat per serving than referenced product.
What does Saturated Fat-Free mean?
Less than 0.2 g of saturated and 0.2 g of trans fats.