6 Lipids Copyright 2016 Cengage Learning All Rights

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6 Lipids Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned,

6 Lipids Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.

LEARNING OUTCOMES 1 List and describe the major types, functions, and structures of lipids.

LEARNING OUTCOMES 1 List and describe the major types, functions, and structures of lipids. 2 Differentiate among essential, conditionally essential, and nonessential fatty acids. 3 Describe the differences among mono-, di-, and triglycerides. 4 Discuss the functions of phospholipids and sterols. 5 Explain the processes of triglyceride digestion, absorption, and circulation. Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 2

LEARNING OUTCOMES 6 List and describe the types and functions of the various lipoproteins.

LEARNING OUTCOMES 6 List and describe the types and functions of the various lipoproteins. 7 Explain the impact of lipids on your health. 8 Understand be able to implement dietary recommendations for lipids. Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 3

What Are Lipids? • Organic macronutrients • Insoluble in water - Hydrophobic • Roles

What Are Lipids? • Organic macronutrients • Insoluble in water - Hydrophobic • Roles of lipids • Oil • Liquid at room temperature • Fat • Solid at room temperature • Major lipids Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 4

What Are Lipids? • Fatty acids • Most abundant type of lipid in body

What Are Lipids? • Fatty acids • Most abundant type of lipid in body and diet • Structure - Carbon chain ▶ Alpha end – carboxylic acid group ▶ Omega end – methyl group • Types - Number of carbons - Types and locations of chemical bonds Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 5

FIGURE 6. 1 Fatty Acid Structure Copyright © 2016 Cengage Learning. All Rights Reserved.

FIGURE 6. 1 Fatty Acid Structure Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 6

What Are Lipids? • Fatty acids • Chain length - Most naturally-occurring fatty acids

What Are Lipids? • Fatty acids • Chain length - Most naturally-occurring fatty acids have even number - Short-chain, medium-chain, and longchain fatty acids - Chemical properties - Physiological functions - Solubility in water Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 7

FIGURE 6. 2 Fatty Acids Can Have Different Chain Lengths Copyright © 2016 Cengage

FIGURE 6. 2 Fatty Acids Can Have Different Chain Lengths Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 8

What Are Lipids? • Fatty acids • Chemical bonds - Single bonds ▸ Saturated

What Are Lipids? • Fatty acids • Chemical bonds - Single bonds ▸ Saturated fatty acids (SFAs) - Double bonds ▸ Monounsaturated fatty acids (MUFAs) ▸ Polyunsaturated fatty acids (PUFAs) - Chemical nature Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 9

FIGURE 6. 3 Saturated and Unsaturated Fatty Acids Copyright © 2016 Cengage Learning. All

FIGURE 6. 3 Saturated and Unsaturated Fatty Acids Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 10

What Are Lipids? • Fatty acids • Cis double bonds - Hydrogens on same

What Are Lipids? • Fatty acids • Cis double bonds - Hydrogens on same side of double bond • Trans double bond - Hydrogens on opposite sides of double bond • Trans fatty acids in food - Naturally occurring - Hydrogenation Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 11

FIGURE 6. 4 Cis versus Trans Fatty Acids Copyright © 2016 Cengage Learning. All

FIGURE 6. 4 Cis versus Trans Fatty Acids Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 12

What Are Lipids? • Naming fatty acids • Characteristics • Alpha naming system -

What Are Lipids? • Naming fatty acids • Characteristics • Alpha naming system - Relative to carboxylic acid end • Omega naming system - Double bond’s distance from the methyl end ▶ Omega-3 and omega-6 fatty acids • Common names Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 13

FIGURE 6. 5 The Alpha (α) Naming System Copyright © 2016 Cengage Learning. All

FIGURE 6. 5 The Alpha (α) Naming System Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 14

What Are Essential, Conditionally Essential, and Nonessential Fatty Acids? • Essential fatty acids •

What Are Essential, Conditionally Essential, and Nonessential Fatty Acids? • Essential fatty acids • Linoleic acid - 18 carbons; two double bonds; omega 6 fatty acid - Arachidonic acid • Linolenic acid - 18 carbons; three double bonds; omega-3 fatty acid - EPA ▸ DHA Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 15

What Are Essential, Conditionally Essential, and Nonessential Fatty Acids? • Essential fatty acids •

What Are Essential, Conditionally Essential, and Nonessential Fatty Acids? • Essential fatty acids • Eicosanoids - Roles - Omega-6 eicosanoids ▸ Cause inflammation and constriction of blood vessels - Omega-3 eicosanoids ▸ Reduce inflammation and stimulate dilation of blood vessels Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 16

FIGURE 6. 6 Fatty Acid Metabolism and Eicosanoid Formation Copyright © 2016 Cengage Learning.

FIGURE 6. 6 Fatty Acid Metabolism and Eicosanoid Formation Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 17

What Are Essential, Conditionally Essential, and Nonessential Fatty Acids? • Essential fatty acids •

What Are Essential, Conditionally Essential, and Nonessential Fatty Acids? • Essential fatty acids • Deficiency - Primary ▸ Rare - Secondary ▸ Diseases that disrupt lipid absorption ▸ Cystic fibrosis Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 18

What Are Essential, Conditionally Essential, and Nonessential Fatty Acids? • Conditionally essential fatty acids

What Are Essential, Conditionally Essential, and Nonessential Fatty Acids? • Conditionally essential fatty acids • Infancy - Arachidonic acid - DHA • Dietary sources of fatty acids • Linoleic acid • Linolenic acid • EPA and DHA Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 19

What Are Essential, Conditionally Essential, and Nonessential Fatty Acids? • Nonessential fatty acids •

What Are Essential, Conditionally Essential, and Nonessential Fatty Acids? • Nonessential fatty acids • Dietary sources - SFAs - PUFAs - MUFAs • Roles Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 20

What Is the Difference between Mono-, Di-, and Triglycerides? • Number of fatty acids

What Is the Difference between Mono-, Di-, and Triglycerides? • Number of fatty acids in chemical structure • Saturation of fatty acids • Lipogenesis • Fatty acids combine with glycerol Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 21

FIGURE 6. 8 Triglyceride Structure Copyright © 2016 Cengage Learning. All Rights Reserved. May

FIGURE 6. 8 Triglyceride Structure Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 22

What Is the Difference between Mono-, Di-, and Triglycerides? • Triglycerides • Richest source

What Is the Difference between Mono-, Di-, and Triglycerides? • Triglycerides • Richest source of energy - 9 kcal per gram • Lipolysis - β-oxidation • Ketones - Ketogenesis Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 23

What Is the Difference between Mono-, Di-, and Triglycerides? • Triglycerides • Storage in

What Is the Difference between Mono-, Di-, and Triglycerides? • Triglycerides • Storage in adipose tissue - Adipocytes - Stored as triglycerides ▸ Advantages • Location of adipose tissue - Subcutaneous vs. visceral adipose tissue • Role of insulin • Insulation Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 24

What Are Phospholipids and Sterols? • Roles • Cell membranes • Transport of lipids

What Are Phospholipids and Sterols? • Roles • Cell membranes • Transport of lipids in bloodstream • No dietary requirements for either of them Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 25

What Are Phospholipids and Sterols? • Phospholipids • • Has two fatty acids Phosphate-containing

What Are Phospholipids and Sterols? • Phospholipids • • Has two fatty acids Phosphate-containing hydrophilic head Amphipathic Roles - Cell membranes - Digestion, absorption, and transport of lipids - Other functions Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 26

FIGURE 6. 10 Cell Membrane Made from Phospholipid Bilayer Copyright © 2016 Cengage Learning.

FIGURE 6. 10 Cell Membrane Made from Phospholipid Bilayer Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 27

What Are Phospholipids and Sterols? • Sterols • Multi-ring structure • Cholesterol - Synthesis

What Are Phospholipids and Sterols? • Sterols • Multi-ring structure • Cholesterol - Synthesis of bile acid - Component of cell membranes - Reproductive hormones - Other roles • Sources • Phytosterols Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 28

FIGURE 6. 12 Cholesterol Content of Selected Foods Copyright © 2016 Cengage Learning. All

FIGURE 6. 12 Cholesterol Content of Selected Foods Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 29

How Are Triglycerides Digested, Absorbed, and Circulated? • Basic goal of digestion • Mouth

How Are Triglycerides Digested, Absorbed, and Circulated? • Basic goal of digestion • Mouth • Lingual lipase • Stomach • Gastrin - Gastric lipase Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 30

How Are Triglycerides Digested, Absorbed, and Circulated? • Small intestine • Phase 1: Micelle

How Are Triglycerides Digested, Absorbed, and Circulated? • Small intestine • Phase 1: Micelle formation - Bile disperses large globules into smaller droplets ▸ Emulsification - Gallbladder disease ▸ Removal of gallbladder Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 31

FIGURE 6. 14 Emulsification of Lipids to Form Micelles in the Small Intestine Copyright

FIGURE 6. 14 Emulsification of Lipids to Form Micelles in the Small Intestine Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 32

How Are Triglycerides Digested, Absorbed, and Circulated? • Small intestine • Phase 2: Pancreatic

How Are Triglycerides Digested, Absorbed, and Circulated? • Small intestine • Phase 2: Pancreatic lipase - Secretin ▸ Release of pancreatic lipase • Final products of lipid digestion - Fatty acids - Glycerol - Monoglycerides Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 33

How Are Triglycerides Digested, Absorbed, and Circulated? • Absorption • Two ways - Unassisted

How Are Triglycerides Digested, Absorbed, and Circulated? • Absorption • Two ways - Unassisted transport into intestinal cells ▶ Short- and medium-chain fatty acids - Repackaging into micelles in lumen ▶ Contents released into intestinal cell’s interior Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 34

How Are Triglycerides Digested, Absorbed, and Circulated? • Circulation • Depends on hydrophilic nature

How Are Triglycerides Digested, Absorbed, and Circulated? • Circulation • Depends on hydrophilic nature of lipid - More hydrophilic ▸ Circulation in blood attached to albumin ▸ Circulates to liver - Less hydrophilic ▸ Circulated in lymph ▸ Lipoproteins ▸ Liporotein lipase Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 35

FIGURE 6. 15 Absorption and Circulation of Lipids Copyright © 2016 Cengage Learning. All

FIGURE 6. 15 Absorption and Circulation of Lipids Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 36

What Are the Types and Functions of Various Lipoproteins? • Produced in the liver

What Are the Types and Functions of Various Lipoproteins? • Produced in the liver • Transport lipids in the blood • Complex globular structures - Apoprotein • Chylomicron • Largest and least dense • Produced in small intestine • Transport dietary lipids exclusively Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 37

FIGURE 6. 17 Origins and Major Functions of Lipoproteins Copyright © 2016 Cengage Learning.

FIGURE 6. 17 Origins and Major Functions of Lipoproteins Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 38

What Are the Types and Functions of Various Lipoproteins? • Very low-density lipoprotein (VLDL)

What Are the Types and Functions of Various Lipoproteins? • Very low-density lipoprotein (VLDL) • Lower lipid-to-protein ratio than chylomicra • Primary function • Low-density lipoproteins (LDL) • LDL receptors • “Bad” cholesterol - Plaque • Intermediate-density lipoprotein (IDL) Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 39

What Are the Types and Functions of Various Lipoproteins? • High-density lipoproteins (HDL) •

What Are the Types and Functions of Various Lipoproteins? • High-density lipoproteins (HDL) • Lowest lipid-to-protein ratio • Collect excess cholesterol - Transport it back to the liver • “Good” cholesterol • Different types - Not equally effective in removing cholesterol Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 40

How Are Dietary Lipids Related to Health? • High-fat foods and obesity • Major

How Are Dietary Lipids Related to Health? • High-fat foods and obesity • Major public health concern • Associated health risks Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 41

How Are Dietary Lipids Related to Health? • Cardiovascular disease • Common types -

How Are Dietary Lipids Related to Health? • Cardiovascular disease • Common types - Heart disease - Stroke • Atherosclerosis • Blood clot - Aneurysm • Lipids of concern • Genetics Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 42

FIGURE 6. 18 Causes of Cardiovascular Disease Copyright © 2016 Cengage Learning. All Rights

FIGURE 6. 18 Causes of Cardiovascular Disease Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 43

How Are Dietary Lipids Related to Health? • Cardiovascular disease • Nutritional guidelines -

How Are Dietary Lipids Related to Health? • Cardiovascular disease • Nutritional guidelines - Moderate overall energy intake - Balance your macronutrients - Whole grains - Dietary fiber • Cancer • Recommendations Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 44

What Are Some Overall Dietary Recommendations for Lipids? • Essential fatty acids • Consume

What Are Some Overall Dietary Recommendations for Lipids? • Essential fatty acids • Consume adequate amounts - DRIs ▸ AIs • Omega-3 fatty acid intake • Limit cholesterol, SFAs, and trans fat • Dietary guidelines • Total lipid consumption • AMDRs Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 45

FIGURE 6. 19 Reading Nutrition Facts Panels Copyright © 2016 Cengage Learning. All Rights

FIGURE 6. 19 Reading Nutrition Facts Panels Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 46

Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or

Copyright © 2016 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. 47