11

22

Notes: What are lipids?Notes: What are lipids?

A family of chemical A family of chemical compounds that are a compounds that are a main component in main component in every living cell.every living cell.

They are organic and They are organic and have carbon chains have carbon chains with attached with attached hydrogen atoms and hydrogen atoms and a carboxyl group at a carboxyl group at one end.one end.

FAT CELL

33

Notes: 3 types of LipidsNotes: 3 types of Lipids 1) 1) PhospholipidsPhospholipids-used as emulsifyers-used as emulsifyers

2) 2) SterolsSterols-bile acids and certain hormones (found in -bile acids and certain hormones (found in both plants and animal foods, but cholesterol is only both plants and animal foods, but cholesterol is only found in animal foods)found in animal foods)

3) 3) TriglyceridesTriglycerides-largest group (fats/oils)-largest group (fats/oils)

Chapter 16 - Text p. 239Chapter 16 - Text p. 239

44

1) Phospholipids: dissolve in both fat and 1) Phospholipids: dissolve in both fat and water. Used as emulsifiers that mix fats water. Used as emulsifiers that mix fats with water products like mayonnaise. with water products like mayonnaise. (Components of cell membranes)(Components of cell membranes)

55

  2) Sterols: include bile acids, and certain hormones that 2) Sterols: include bile acids, and certain hormones that carry out vital functions. Both plants and animals foods carry out vital functions. Both plants and animals foods have sterols, but the most well known,-cholesterol is only have sterols, but the most well known,-cholesterol is only found in animal food sourcesfound in animal food sources

-cholesterol is used for digesting fat and making -cholesterol is used for digesting fat and making vitamin D, making some hormones, and building vitamin D, making some hormones, and building cells. Our bodies make all the cholesterol we need cells. Our bodies make all the cholesterol we need but we still get it animal foods.but we still get it animal foods.

Cholesterol is a complex molecule its formula isCholesterol is a complex molecule its formula is::CC2727HH4545OHOH

66

3) Triglycerides (“fat”): the largest class of 3) Triglycerides (“fat”): the largest class of lipids which includes all of the fats and oils lipids which includes all of the fats and oils we typically eat.we typically eat.

-stored as adipose tissue: pockets of fat -stored as adipose tissue: pockets of fat storing adipose cells storing adipose cells

Figure: 16-1Figure: 16-1

77

Notes: Forms of fatNotes: Forms of fat

Animal sourcesAnimal sources Butter Butter LardLard

Eating different types Eating different types of fat can have of fat can have different effects on different effects on the body.the body.

Plant sourcesPlant sources MargarineMargarine Oils Oils ShorteningShortening

88

Notes: Fat per dayNotes: Fat per day 30 % of your calorie30 % of your calorie

intake or lessintake or less

Fat= 9 calorie per gramFat= 9 calorie per gram

(sugar was 4 calories (sugar was 4 calories per gram)per gram)

99

Women 19-49yrs 65 gms 16 tspWomen 19-49yrs 65 gms 16 tsp Men 19-49 90 gms 22 tspMen 19-49 90 gms 22 tsp 50+ 60 gms 15 50+ 60 gms 15

1 tsp = 4-5 g fat 1 tsp = 4-5 g fat

1010

Notes: What is a Carboxyl Notes: What is a Carboxyl group -COOH ?group -COOH ?

1111

Notes: Structure of TriglyceridesNotes: Structure of Triglycerides

Fats are made from Fats are made from glycerol and fatty glycerol and fatty acids.acids.

Each glycerol is Each glycerol is attached to 3 fatty attached to 3 fatty acids.acids.

They contain carbon , They contain carbon , hydrogen and oxygenhydrogen and oxygen

1212

triglyceridetriglyceride

1313

Notes: Fatty AcidsNotes: Fatty Acids

These are the organic acids in triglyceridesThese are the organic acids in triglycerides They have a carbon chain with attached They have a carbon chain with attached

hydrogen atoms and a carboxyl group (-COOH) hydrogen atoms and a carboxyl group (-COOH) at one end. (Figure 16-2)at one end. (Figure 16-2)

The simplest fatty acid has a two carbon chain The simplest fatty acid has a two carbon chain (acetic acid p. 241 fig. 16-3)(acetic acid p. 241 fig. 16-3)

3 react with glycerol to from a “triglyceride”3 react with glycerol to from a “triglyceride”(Figure 16-4 p. 241)(Figure 16-4 p. 241)

1414

Notes: Essential Fatty Acids Notes: Essential Fatty Acids (EFA’s) (EFA’s)

Are those the body must Are those the body must get through food as we get through food as we cannot make them.cannot make them.

They are linoleic and They are linoleic and linolenic fatty acidslinolenic fatty acids

Are needed for normal Are needed for normal growth and development.growth and development.

Found in: veggies, grains, Found in: veggies, grains, nuts, seeds, and nuts, seeds, and soybeanssoybeans

1515

Notes: Fatty Acids and BondingNotes: Fatty Acids and Bonding

FA’s carbon atoms are joined in covalent FA’s carbon atoms are joined in covalent bonds that are either single bonds or bonds that are either single bonds or double bonds.double bonds.

These bonds help to distinguish between These bonds help to distinguish between saturated and unsaturated fats.saturated and unsaturated fats.

Text p. 240-241, figure 16-5Text p. 240-241, figure 16-5

1616

Notes: Saturated fatsNotes: Saturated fats

Animal sourcesAnimal sources Fatty acids are Fatty acids are

saturated-hold all the saturated-hold all the hydrogen atoms they hydrogen atoms they can.can.

Solid at room Solid at room temperaturetemperature

We make our own.We make our own.

1717

SourcesSources

Animal productsAnimal products

1818

Notes: Unsaturated fatsNotes: Unsaturated fats

Missing hydrogen bonds so Missing hydrogen bonds so single bonds cannot form, single bonds cannot form, instead, a double bond instead, a double bond formsforms

2 carbon atoms missing a 2 carbon atoms missing a hydrogen bond join togetherhydrogen bond join together

Can be monounsaturated or Can be monounsaturated or polyunsaturated.polyunsaturated.

Liquids at room temperatureLiquids at room temperature Question: Is their a mistake Question: Is their a mistake

in this diagram?in this diagram?

1919

Again Mistakes in diagram?Again Mistakes in diagram?

Monounsaturated - Monounsaturated - lacks 2 hydrogen- has lacks 2 hydrogen- has one double bond one double bond

Polyunsaturated- Polyunsaturated- lacks more than 2 lacks more than 2 hydrogen- 2 or more hydrogen- 2 or more double bondsdouble bonds

2020

MOnounsaturated

monounsaturated

Saturated

2121

Notes: Cis vs. Trans Fatty Notes: Cis vs. Trans Fatty AcidsAcids

Unsaturated fatty acids are “kinked” at the Unsaturated fatty acids are “kinked” at the double bonds between carbon atoms.double bonds between carbon atoms.

If the hydrogen atoms are missing from the If the hydrogen atoms are missing from the same side of the double bonded carbon atoms same side of the double bonded carbon atoms this is called the this is called the ciscis configuration. configuration.

If the hydrogen atoms are missing from opposite If the hydrogen atoms are missing from opposite sides of the double bonded carbon atoms this is sides of the double bonded carbon atoms this is called the called the transtrans configuration. configuration.

2222

Notes: Properties of Notes: Properties of triglyceridestriglycerides

9 calories per gram 9 calories per gram Only slightly soluble in water Only slightly soluble in water The have phase differences (liquid vs. solid)The have phase differences (liquid vs. solid) Fats melt at different temperaturesFats melt at different temperatures Solidification point-Solidification point- temperature at which a temperature at which a

melted fat regains its original firmness.melted fat regains its original firmness.

2323

Notes: Fats in Food Notes: Fats in Food

Provide essential fatty Provide essential fatty acids acids

Transport fat soluble Transport fat soluble Vitamins A D E K Vitamins A D E K

Sensory appealSensory appeal TenderizeTenderize AerationAeration Influence emulsionsInfluence emulsions Add flavourAdd flavour Rancid as fats oxidizeRancid as fats oxidize

2424

Make foods taste betterMake foods taste better

2525

Notes: Commercial use and Notes: Commercial use and cooking with fatscooking with fats

Commercially: (2 groups)Commercially: (2 groups) A) animal fatsA) animal fats B) plant oilsB) plant oils

Plant oils undergo Plant oils undergo hydrogenation hydrogenation a a process that adds hydrogen to process that adds hydrogen to unsaturated fat breaking some double unsaturated fat breaking some double bonds replacing them with single ones. bonds replacing them with single ones. Example: Vegetable shortening (solid)Example: Vegetable shortening (solid)

2626

Hydrogenated Vegetable oilHydrogenated Vegetable oil

The process of adding hydrogen to The process of adding hydrogen to unsaturated fatty acids unsaturated fatty acids

GoodGood- Makes them resistant to oxidation- - Makes them resistant to oxidation- go rancid more slowlygo rancid more slowly

GoodGood- makes them more stable- makes them more stable BadBad- makes them more saturated - makes them more saturated

2727

Notes: Trans fatty acidsNotes: Trans fatty acids

Occur when Occur when hydrogenation is done hydrogenation is done the unsaturated fats the unsaturated fats become saturatedbecome saturated

Hardened margarines Hardened margarines

2828

Smoking point Smoking point

The point at which a The point at which a fat begins to give off fat begins to give off smoke when heated.smoke when heated.

High- peanut, canolaHigh- peanut, canola Low- butterLow- butter

2929

Olestra- artificial fatOlestra- artificial fat

Remains undigestedRemains undigested Passes through the Passes through the

digestive tract intactdigestive tract intact Had too many bad Had too many bad

side effects side effects

3030

Notes: Use of fats in the bodyNotes: Use of fats in the body

1. Energy1. Energy 2. Fat storage – for later use 2. Fat storage – for later use 3. Shock absorbers for the vital organs3. Shock absorbers for the vital organs 4. Satiety value – makes us feel full longer4. Satiety value – makes us feel full longer 5. fats are converted to other compounds- 5. fats are converted to other compounds-

hormones, bile, Vitamin Dhormones, bile, Vitamin D

3131

6. Insulates – a fat blanket under 6. Insulates – a fat blanket under the skinthe skin

3232

Notes:CholesterolNotes:Cholesterol

Used to make bileUsed to make bile Causes build up of plaque in the arteriesCauses build up of plaque in the arteries Found in animal sources Found in animal sources Cause cardiovascular diseaseCause cardiovascular disease 2 types: LDL and HDL2 types: LDL and HDL

(travel in lipoproteins)(travel in lipoproteins) Figure 16-9Figure 16-9

3333

LDL cholesterolLDL cholesterol[ bad][ bad]

Carries cholesterol to Carries cholesterol to to the body tissues to to the body tissues to deposit theredeposit there

When elevated When elevated forecast heart and forecast heart and artery diseaseartery disease

Oxidation of LDL Oxidation of LDL causes damage to causes damage to arteriesarteries

3434

HDL cholesterolHDL cholesterol[good][good]

HDL cholesterol- HDL cholesterol- carries cholesterol carries cholesterol away from tissueaway from tissue

3535

AntioxidantsAntioxidants

Slows oxidation of Slows oxidation of LDLLDL

Vitamin C, Vitamin E, Vitamin C, Vitamin E, selenium are selenium are antioxidantsantioxidants

3636

Why exercise?Why exercise?

Develops higher HDLDevelops higher HDL Circulation improves Circulation improves Larger volume of Larger volume of

blood pumped each blood pumped each heart beat , reducing heart beat , reducing heart’s workload heart’s workload

Overall leaner body- Overall leaner body- reducing riskreducing risk

3737

3838

Omega-6 Fatty acidsOmega-6 Fatty acids

Omega-6 fatty acids Omega-6 fatty acids belong to a group of belong to a group of "good" fats called "good" fats called polyunsaturated fatty polyunsaturated fatty acids. acids.

Help with immune Help with immune systemsystem

Relax Relax

Good dietary sourcesGood dietary sources of omega-3 fatty of omega-3 fatty acidsacids

3939

Sources of fat in average dietSources of fat in average diet

Fresh meat = 8.5 %Fresh meat = 8.5 % Processed meat = 11%Processed meat = 11% Poultry =2.5Poultry =2.5 Meat alternatives =7%Meat alternatives =7% Milk =6%Milk =6% Milk products = 18%Milk products = 18% Veg and Fruit =2%Veg and Fruit =2% Baked goods=9.5%Baked goods=9.5% Fats and oils=31%Fats and oils=31%