Question

FNES 263 Exam 3 Review Sheet Lipids How fats verses oils are defined Explain the basic chemical structure of triglycerides, phospholipids, cholesterol Definition of short, medium and long chain fatty acid Know the nomenclature of fatty acids and how their chemical structure differs Digestion, Absorption and Transport o know each step of digestion, absorption, and transport of lipids in the body o Including the function of lipoproteins, and major content of each lipoprotein . Function O Describe the functions of triglycerides, phospholipids and cholesterol in the body O Function of bile Food sources of fats as shown in Choose My Foods booklet • Major food sources of saturated fats, monounsaturated fats, particularly added fats . Know if dietary sources of cholesterol and whether it is essential to include cholesterol or phospholipids in our diet Know the food sources of EPA, DHA Know the names of the two essential fatty acids and food sources Know the American Heart Association (AHA) guidelines for percent saturated fat and trans fat Know whether the goal is to raise or lower LDL, HDL Know the recommendations to modify HDL Know the type of fatty acid and definition of eicosanoids

Answer 1

1. The most obvious and defining difference between fatsand oils is that fats are typically solid at room temperature whereas oils are liquid at room temperature.

2. Triglycerides are tri-esters consisting of a glycerol bound to three fatty acid molecules.The structure of the phospholipid molecule generally consists of two hydrophobic fatty acid "tails" and a hydrophilic "head" consisting of a phosphate group.Cholesterol is a lipid with a unique structureconsisting of four fused hydrocarbon rings forming the bulky steroid structure.

3. Short-chain fatty acids (SCFAs) are fatty acids with fewer than six carbon atoms.Medium-chain triglycerides are triglycerides with two or three fatty acids having an aliphatic tail of 6–12 carbon atoms. Long-chain fatty acids (LCFA) are fatty acids with aliphatic tails of 13 to 21 carbons.

4. In IUPAC nomenclature, fatty acids have an [-oic acid] suffix. In common nomenclature, the suffix is usually -ic. The shortest descriptions of fatty acids include only the number of carbon atoms and double bonds in them (e.g. C18:0 or 18:0).Most fatty acidscontain an even number of carbon atoms in the hydrocarbon chain and follow the general molecular formula of CH3(CH2)xCOOH where x is the number of carbon atoms in the hydrocarbon chain.

5. The digestion of certain fats begins in the mouth, where short-chain lipids break down into diglycerides because of lingual lipase. Absorption and Transport into Blood. The major products of lipid digestion - fatty acids and 2-monoglycerides - enter the enterocyte by simple diffusion across the plasma membrane.

6. Functions

Triglycerides provide your body with energy, but their main function is to store energy for later use. The food you eat contains calories in the form of carbohydrates, protein and fat

Phospholipids provide barriers in cellular membranes to protect the cell, and they make barriers for the organelles within those cells. Phospholipids work to provide pathways for various substances across membranes.

Cholesterol is essential for making the cell membrane and cell structures and is vital for synthesis of hormones, vitamin D and other substances. Cell membrane synthesis – Cholesterol helps to regulate membrane fluidity over the range of physiological temperatures.

Bile contains bile acids, which are critical for digestion and absorption of fats and fat-soluble vitamins in the small intestine.

7. Food sources for fat are avocados, cheese, whole eggs, fatty fish .
8.Sources of monounsaturated fat include :avocados.almonds, cashews and peanuts.cooking oils made from plants or seeds like canola, olive peanut, soybean, rice bran, sesame and sunflower oils.

Food sources for saturated fats are fatty beef, lamb, pork, poultry, beef fat, butter.

9. Cholesterol is found in animal foods. Animal foods include meats, poultry, fish, eggs, and milk products. Phospholipids are essentially added in diet.
10.Fatty, oily fish is an excellent source of DHA and EPA, which are two key types of omega-3 fatty acid.

11.omega-6 fatty acid linoleic acid (LA), and its derivatives, gamma-linolenic acid (GLA) and arachidonic acid(AA) the omega-3 fatty acid alpha-linolenic acid (ALA) and its derivatives, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

Seaweed and algae. Seaweed is a nutrient-dense food , fatty fish are excellent sources.

12. AHA recommends a.5% to 6% of calories from saturated fat, limit trans fat to less than 1% of your dailycalories.

13.HDL levels should be kept higher. Lower LDL.
14.Niacin, a B vitamin, has long been used to increasehigh-density lipoprotein (HDL) cholesterol. consime olive oil also.

15.There are three types of fatty acids: saturated, monounsaturated, and polyunsaturated.

Eicosanoids are signaling molecules made by the enzymatic or non-enzymatic oxidation of arachidonic acid or other polyunsaturated fatty acids (PUFAs) that are, similar to arachidonic acid, 20 carbon units in length.