Ch 8: Fats Flashcards
Functions of Fats
Source of Energy
Metabolism of Fat Soluble Vitamins
Obtaining Essential Fatty Acids
Structure of Lipids
Repeating units of Fatty Acids
Comprised of hydrogen, carbons, and oxygen
Types of Lipids
Simple Lipids (Fatty Acids)
Compound Lipids (Phospholipids)
Derived Lipids (Cholesterol)
Fatty Acids
Organic Compounds with Long Hydrocarbon Chains that are Saturated or Unsaturated
At one end of the hydrocarbon chain is a carboxyl group (COOH). This carboxyl group is what makes a fatty acid an acid (carboxylic acid).
Phospholipids
Comprised of 2 Fatty Acids, a Phosphate Group and a Glycerol Molecule (form Cell Membrane)
Head is Water Soluble (Hydrophilic)
Tail is Hydrophobic (Not Water Soluble)
Saturated Fats
Fatty Acids with a Maximum number of Hydrogen molecules and contain only Single bonds between their Carbon atoms
Examples of Saturated Fats
Animal Fat, Palm Oil and Coconut Oil, Grains based desserts, Lard
Unsaturated
Fatty Acids that have one or more double bonds between the Carbon atoms in the Carbon chain
Prone to Oxidative Damage
Hydrogenation
Process of forcing Hydrogen into Vegetable Oil to create a Semi-Solid or Solid Saturated Fat
Oxidative Damage
Imbalance of Free Radicals and Antioxidants
Free Radicals have an uneven number of electrons which makes them more likely to react
Monosaturated Fatty Acids (MUFAs)
Unsaturated fats that have one unsaturated carbon molecule (two hydrogen atoms instead of four) or one double bond
Polysaturated Fatty Acids (PUFAs)
Unsaturated fats that have two or more double bonds between carbon molecules.
Trans Fats
An artificial fatty acid that occurs when hydrogen is added to liquid vegetable oils (unsaturated fat) to make them more solid (saturated fat) and have a more stable shelf life.
Primary source of trans fat is partially hydrogenated oils (PHOs) such as margarine and vegetable shortening, as well as fried foods such as French fries, doughnuts, fried chicken, baked goods, snacks, and nondairy coffee creamer.
Sources of MUFAs
Oil Oil, Nuts (Almonds, Cashews and Pecans), Canola Oil, Avocados, Olives and Nut Butters
Polyunsaturated Fats (PUFAs)
Unsaturated Fats that have 2 or more double bonds between Carbon molecules
Examples of PUFAs
Walnuts, sunflower seeds, flax oil, Salmon and corn, soybean and safflower oil,
Low-Density Lipoprotein (LDL)
Transmits cholesterol from the Liver to the Cells
Triglycerides (TG)
Primary storage and transportable form of fats in the body, composed of three fatty acids bound to a Glycerol backbone
Composes most of Adipose Tissue
Transports food in the bloodstream
High-Density Lipoprotein (HDL)
Lipoprotein that carries excess cholesterol away from the cells to the Liver which is then turns to Bile
Low in Daily Value (DV) of a Nutrient
5% or less
High in Daily Value (DV) of a Nutrient
20% or more
Compound Lipids
Phospholipids and Lipoproteins
Phospholipids
Comprised of two Fatty Acids, a Phosphate Group and a Glycerol molecule. Head = Water Soluble Tail = Water Insoluble
Forms Cell Membrane
Lipoproteins
Comprised of Fat and Protein that transports Cholesterol and other Lipids to and from various tissues in the blood
Essential Fatty Acids
Omega-3s (a-Linolenic) and Omega-6s (a-Linoleic)
Omega-3s (a-Linolenic)
Named based on the position of the first double bond in the carbon chain, Carbon 3, an essential polyunsaturated fatty acid that is found in fish, seafood, flaxseed oil, and walnuts.
Omega-6s (a-Linoleic)
Named based on the position of the first double bond in the carbon chain, Carbon 6, an essential polyunsaturated fatty acid that is found primarily in plant oils such as corn, soybean, and safflower.
EPA (Eicosapentaenoic acid)
Essential Omega-3 Fatty Acid found in marine sources including fish and krill, serves as a precursor to various compounds that have anti-inflammatory activities in the body in addition to serving as structural components of the brain and eye tissue.
DHA (Docosahexaenoic acid)
Essential omega-3 fatty acid found in marine sources including fish and krill, highly abundant in the human brain, eyes, and sperm cells.
Benefits of Omega-3 Fatty Acids
Rheumatoid Arthritis, Fetal Development (Eye and Brain), Depression, possibly Alzheimer’s
Adequate Intake for Omega-3 Fatty Acids
The adequate intake (AI) for omega-3 fatty acid is 1.6 grams and 1.1 grams per day for males and females (ages 14 to 51+ years), respectively.
Stomach effect on Fats
Gastric Lipase break down Triglycerides into Diglycerides and Free Fatty Acids
Small Intestine effect on Fats
A small amount of bile, an emulsifier, is released, which attracts fat molecules and holds onto them while being held by the water. Next, pancreatic lipases break down triglycerides into monoglycerides and free fatty acids
Micelle
A compound comprised of Bile Salts, Surrounding Monoglycerides, Free Fatty Acids and Fat Soluble Vitamins for Absorption
Chylomicron
Triglycerides, Cholesterol and Phospholipids plus a Protein Carrier
What delivers Triglycerides to the cells of the body?
Chylomicrons (from digestion) and very-low-density lipoproteins (VLDLs) both move through the bloodstream to deliver triglycerides to the cells of the body with the help of Lipase
Desirable Level of LDL
Under 100 mg/dL
Desirable Level of HDL
Over 60 mg/dL
Desirable Level of Triglycerides
Under 150 mg/dL
Beta-Oxidation
The process that occurs within the cell’s mitochondria to produce glycerol and fatty acids.
Acetyl-CoA
A molecule that participates in biochemical reactions in protein, carbohydrate, and lipid metabolism, producing energy.
Dietary Calories from Saturated Fat
Less than 10% Replace with PUFAs
Focus on consuming PUFAs, including omega-3s and omega-6s food sources. Dietary PUFAs may lower serum VLDL and LDL concentrations. This is because the liver converts PUFAs into ketone bodies instead of VLDLs, which transport triglycerides to the cells.
Establishes nutrition guidelines based on scientific evidence for the United States and Canada
Institute of Medicine of the National Academies
Acceptable macronutrient distribution range (AMDRs) for fat
Between 20% to 35% of total calories per day for dietary total fat
10% of total calories per day for dietary Saturated fat
Dietary Guidelines for Americans
A variety of vegetables from all the subgroups—dark green, red and orange, legumes (beans and peas), starchy, and other
Fruits, especially whole fruit
Fat-free or low-fat dairy, including milk, yogurt, cheese, and/or fortified soy beverages
A variety of protein foods, including seafood, lean meats and poultry, eggs, and legumes, and nuts, seeds, and soy products
Monounsaturated and polyunsaturated oils
Limiting saturated fats to 10% of total calories per day and avoiding trans fats
