Nutrition Ch 5: Lipids Mimi Main

What are the four categories for meat and how are they determined?

Four categories based on fat contents 1. very lean: ground round is 10% fat 2. lean: commercial ground turkey is 15% fat 3. medium-fat: ground chuck is 16% fat 4. high-fat: regular ground beef is 23% fat

Glucose is stored as _____ in liver and muscles. Excess glucose can be converted to ______, but it is an inefficient process. Glucose is necessary for the complete breakdown of _____

Glucose is stored as *glycogen* in liver and muscles. Excess glucose can be converted to *fat*, but it is an inefficient process. Glucose is necessary for the complete breakdown of *fat*

Key Point Plant sterols in food inhibit _______

cholesterol absorption plant sterols resemble cholesterol in structure and can inhibit cholesterol absorption in the human digestive tract; their effects are currently under study

_________ is the lipoprotein that carries triglycerides from the small intestine to the liver

chylomicron

Define lipoproteins

clusters of lipids associated with protein which serve as txp vehicles for lipids in blood and lymph major lipoproteins: chylomicrons, VLDL, LDL, HDL

______ is the body's chief storage form for the energy from food eaten in excess of need

fat

What are lipases Where do lipases come from? What do they do?

fat digesting enzymes from the pancreas can split fat into smaller particles for absorption

Key Point Phospholipids play key roles in cell _____

membranes

recall that _________ and _________ from digested food fat depend on chylomicrons, a type of lipoprotein, to txp them around the body

monoglycerides and long chain fatty acids

What is the predominant type of fat (triglyceride) found in the following foods? Which foods are likely to contain trans-fat? *cashews*

monounsaturated

What is the predominant type of fat (triglyceride) found in the following foods? Which foods are likely to contain trans-fat? *avocado*

monounsaturated

What is the predominant type of fat (triglyceride) found in the following foods? Which foods are likely to contain trans-fat? *olive oil*

monounsaturated

What is the predominant type of fat (triglyceride) found in the following foods? Which foods are likely to contain trans-fat? *peanut butter*

monounsaturated

What is the predominant type of fat (triglyceride) found in the following foods? Which foods are likely to contain trans-fat? *canola oil*

monounsaturated fat

Most vegetable oils are high in ___________ fats where as olive oil, peanuts oil, canola oil are rich in_______

most vegetable oils are high in pufa olive/peanut/canola oil/avocado (and most nuts and seeds except walnuts) are high in MUFA

Does fat require a lot of chemical steps before being stored as fat in fat cells?

nope. (it is harder for the body to store excess carbs as fat because the conversion is not energy efficient.)

What are good sources of linolenic acid?

oils (canola, flaxseed, soybean, walnut, wheat germ; liquid or soft margarine made from canola oil or soybean oil) -nuts and seeds (flaxseeds, walnust, soybeans) -vegetables (soybeans)

Some vegetable oils such as _________ and ______ are rich in monounsaturated fatty acids.

olive and canola oil (and peanut oil, nuts, avocado)

When I say MUFA food, you should think....

olive oil canola oil peanut oil most nuts/seeds (except walnuts) avocado

given dietary linoleic acid, the body can produce other need members of the omega ___ family such as ________

omega 6 arachidonic acid (notable for its role as a starting material from which a number of eicosanoids are made.

Define triglycerides: What are they composed of?

one of the three main classes of dietary lipids and the chief form of fat in foods and in the human body. Composed of three fatty acids and one glycerol

Define sterols:

one of the three main classes of dietary lipids. Sterols have a structure similar to cholesterol

What is the predominant type of fat (triglyceride) found in the following foods? Which foods are likely to contain trans-fat? *sour cream*

saturated fat

What is the predominant type of fat (triglyceride) found in the following foods? Which foods are likely to contain trans-fat? *butter*

saturated fat

What is the predominant type of fat (triglyceride) found in the following foods? Which foods are likely to contain trans-fat? *coconut oil*

saturated fat

What is the predominant type of fat (triglyceride) found in the following foods? Which foods are likely to contain trans-fat? *whole milk*

saturated fat

What is more influential in raising blood cholesterol than dietary cholesterol?

saturated fat (triglycerides) and trans fat

How do larger digested lipids, monoglycerides and long-chain fatty acids get where they need to go in the body?

unlike glycerol and shorter chain fatty acids, these guys are too big to travel around unassisted. *they get reformed into triglycerides and packaged into chylomicrons (type of lipoprotiein, aka clusters of lipid and protein)*

VLDL

very low density lipoproteins carry triglycerides and other lipids made in the liver to the body cells for their use (the more lipids, the less dense, the more proteins, the more dense)

Vitamin D is a ______ made from ______

vitamin D is a sterol made from cholesterol

When I say PUFA foods, you should think of...

walnuts Most vegetable oils (except olive/canola/peanut oils) flaxseed oil fish and fish oil

Can plants produce cholesterol?

no! only things with a liver can

Are lecithin and cholesterol essential nutrients?

no, your body can make them (essential nutrients are ones you have to eat because you don't make them)

Do we digest fats in our mouths?

nope. an enzyme produced by the tongue plays a major role in digesting milk fat in infants but is of little importance to lipid digestion in adults

What class of fat is lecithin?

phospholipid

Name the class of lipid that helps make up cell membranes and lecithin

phospholipids

some _________ generate signals inside the cells in response to hormones, such as insulin, to help modulate body conditions

phospholipids

Why do unsaturated fatty acids go bad?

points of unsaturation in fatty acids are weak spots that are vulnerable to attack by oxygen damage (oxidation) making the oil rancid and taste off.

What is the predominant type of fat (triglyceride) found in the following foods? Which foods are likely to contain trans-fat? *corn oil*

polyunsaturated

What is the predominant type of fat (triglyceride) found in the following foods? Which foods are likely to contain trans-fat? *safflower oil*

polyunsaturated

What is the predominant type of fat (triglyceride) found in the following foods? Which foods are likely to contain trans-fat? *shrimp*

polyunsaturated

most vegetable and fish oils are rich in _________ fatty acids

polyunsaturated

Define Trans Fats

*fats that contain any number of unusual fatty acids (trans fatty acids) formed during processing*...[derived from pufa (and mufa) that have been hydrogenated and act like saturated fats in the body]

The max saturated fat intake set by the dietary guidelines for americans: 1,600 kcal diet: 2,000 kcal diet: 2,200 kcal diet: 2,500 kcal diet: 2,800 kcal diet:

1600: 18g sat fat 2000: 20 2200: 24g 2500: 25g 2800: 31g

The DRI committee and Dietary Guidelines suggest ____ to ____ % of daily energy should come from fats - less than ____% from saturated fat -less than _____mg cholesterol

20-35% of daily energy from total fat less than 10% from saturated fat less than 300mg cholesterol recall it was 45-65% carb

get ___ to ___% of your total kcal from omega 6 pufa get __ to __% of total kcal from omega 3 pufa

6-10% total kcal from omega 6 1-2% total kcal from omega 3

What is the energy yield of fat?

9 kcal per gram (fats yield concentrated energy)

Key Point: __________are energy-rich carbon chains that can be saturated (filled with hydrogens) or monounsaturated (with only one point of unsaturation) or polyunsaturated (with more than one point of unsaturation)

Fatty acids

______ is the process of adding hydrogen to unsaturated fatty acids to make fat more solid and resistant to the chemical change of oxidation

Hydrogenation

lipoproteins that txp lipids from the liver to other tissues such as muscle and fat

LDL low density lipoproteins transport cholesterol and other lipids to the tissues. LDL is made from VLDL after they have donated many of their triglycerides to body cells (the more lipids, the less dense, the more proteins, the more dense)

Key Point Are supplements of omega-3 fatty acids recommended?

No high intakes of omega-3 polyunsaturated fatty acids may increase bleeding time, interfere with wound healing, raise LDL cholesterol and suppress immune function

_____ + ______ + ______= phospholipid

Phospholipids Glycerol, two fatty acids, and a phosphorus molecule

Key Point True or false, deficiencies of the essential fatty acids are virtually unknown in the united states and canada

TRUE!

The cells of the intestinal lining convert large lipid fragments, such as monoglycerides and long-chain fatty acids, back into _____ and combine them with protein, forming _________ that travel in the ______ to the blood

The cells of the intestinal lining convert large lipid fragments, such as monoglycerides and long-chain fatty acids, back into *triglycerides*and combine them with protein, forming *lipoproteins* that travel in the *lymph* to the blood

lipoproteins that txp triglycerides and other lipids form the liver to various tissues

VLDL

which lipoprotein carries triglycerides and other lipids made in the liver to the body cells for their use?

VLDL

The oil that is highest in polyunsaturated fatty acids is

safflower oil

What is the predominant type of fat (triglyceride) found in the following foods? Which foods are likely to contain trans-fat? *beef*

saturated

trans fats act like ______ fats in the body

saturated

What is the predominant type of fat (triglyceride) found in the following foods? Which foods are likely to contain trans-fat? *ricotta cheese*

saturated fat

Coconut and palm oil defy the rule of most plant oils becuase

they are highly saturated (high in saturated fatty acids)

omega 6 fatty acids are supplied abundantly when you eat ________

vegetable oils

Define point of unsaturation

a site in a molecule where the bonding is such that additional hydrogen atoms can easily be attached

an increasing waistline, in turn, often increases ________

blood triglycerides

Key Point _______ is necessary for the complete breakdown of fat

carbohydrate

The human body usually synthesizes fatty acids from ______, _____ and ______. Two well known exceptions that the body can't make include _____ and ______

carbs/fat/protein. exceptions are the essential fatty acids= linoleic (omega 6) and linolenic (omega 3) acids

the number one killer of adults in the united states and canada

cardiovascular disease

________ is important in the structure of brain and nerve cells (part of every cell)

cholesterol

steroid hormones, including sex hormones, are made from________

cholesterol

_______ serves as the raw material for making emulsifiers in bile, important for fat digestion

cholesterol, a sterol

Key Point Fatty acids in food influence _______ in the body

composition of fats

Arachidonic acid is a member of the ________ family. It is produced by the body, but you need __________ to do this. It is notable for its role as a starting material from which a number of ________ are made

-member of the *omega 6 family* -produced by the body, need *linoleic acid* to do this -notable for role as staring material from which a number of *eicosanoids* are made

Keep saturated fat to less than ____% of total energy

10%

Chylomicrons are _______ particles that consist of _______(85-92%), ________(6-12%), ________(1-3%), and ______(1-2%). They transport dietary lipids from the ______to other locations in the body. Chylomicrons are one of the five major groups of lipoproteins (chylomicrons, VLDL, IDL, LDL, HDL) that enable fats and cholesterol to move within the water-based solution of the bloodstream.

Chylomicrons are *lipoprotein* particles that consist of *triglycerides* (85-92%), *phospholipids* (6-12%), *cholesterol* (1-3%), and *proteins* (1-2%). They transport dietary lipids from the *intestines* to other locations in the body. Chylomicrons are one of the five major groups of lipoproteins (chylomicrons, VLDL, IDL, LDL, HDL) that enable fats and cholesterol to move within the water-based solution of the bloodstream.

Hello, my name is ___________. I am the lipoprotein that carries triglycerides and other lipids made in the liver to the body cells for their use. When I get rid of my triglycerides, then you can call me _________

Very Low Density Lipoprotein (VLDL): carries mostly triglycerides and other lipids, such as cholesterol made in liver to body cells for use. LDL txps mainly cholesterol and other lipids to tissues.

Define Lecithin: Lecithin is a ______ manufactured by the _______ and found in many ________ and is a major constituent of___________

a *phospholipid* manufactured by the *liver* and also found in many *foods* (such as egg yolks); a major constituent of *cell membranes*

Define lipid: Lipids include:

a family of organic (carbon containing) compounds soluble in organic solvents, but not in water. Lipids include triglycerides (fats and oils), phospholipids and sterols

Define saturated fatty acid: Define saturated fat:

a fatty acid carrying the max possible number of hydrogen atoms, and has no points of unsaturation (double bonds). A saturated fat is a triglyceride that contains three saturated fatty acids

inside the ___________, monoglycerides/long chain fatty acids are reformed into ___________ and packaged into ___________ that can safely carry lipids from place to place in the watery blood

inside the intestintal cell triglycerides, chylomicrons inside the *intestinal cell* monoglycerides, long chain fatty acids are reformed into *triglycerides* and packaged into *chylomicrons* that can safely carry lipids from place to place in the watery blood

_______ fats contributes to blood clotting associated with heart attacks, whereas _________ fats oppose blood clotting

saturated fats bad (and trans fats bad), polyunsaturated (and monounsaturated) fats are better.

Can glucose be converted to fat? Can fat be converted to glucose?

animals and plants can convert glucose to fat. fats cannot be converted to glucose

keep trans fat intake

as low as possible less than 1% total kcal

What would you recommend eating as a good source of monounsaturated fatty acids?

avocado, nuts, oils such as canola/olive/peanut/sesame, olives, natural peanut butter, seeds (sesame)

Key Point The body draws on his stored fat for _____

energy

Define arachidonic acid

an omega-6 fatty acid derived from linoleic acid

How do bile and lipase work together?

*-Bile emulsifies and suspends fat droplets within the watery fluids in the small intestine...one end of the bile holds fat and the other end is attracted to water -Then the lipase (fat digesting enzyme from the pancreas) can come split molecules into smaller molecules for absorption. * -What is left? fatty acids, glycerol, monoglycerides, phospholipids, cling together in bile balls and move across watery mucous to absorptive cells of intestinal villi. -glycerol/short chain fatty acids pass through villi into blood stream unaided -monoglycerides/long chain fatty acids can't pass through....in the intestinal cell they reform into triglycerides and are packaged with protein to make chylomicrons to shuttle them to lymph then blood.

What are the 7 known roles of essential fatty acids?

*1. provide raw material for eicosanoids* (group of bioactive lipids that act like hormones and send signals to body tissues to elicit responses) *2. serve as structural and functional parts of cell membranes 3. contribute lipids to brain/nerves 4. promote natural growth and vision 5. maintain outer structures of skin/protecting against water loss 6. help regulate genetic activities affecting metabolism 7. support immune cell functions*

Given dietary linolenic acid, the body can make other members of the omega-3 series. Two family members of great interest to researchers are _____ and ______

*DHA* and *EPA* (note, these are highly unsaturated ) -lower risk of heart disease -cancer prevention -role in cell membranes -role in brain function/vision

How do lipids get across the watery mucus layer of the small intestine?

*bile* shuttles the lipids across the watery mucus layer to the waiting absorptive surfaces on cells of the intestinal villi. the cells then extract the lipids -and the bile can be absorbed/reused or it can flow into intestinal contents and get pooped out.

group of bioactive lipids known as ___________ that act somewhat like hormones--they send signals to body tissues and elicit responses.

*eicosanoids* -need essential fatty acids to make these in the body -influence diverse body functions

-In the small intestine, bile emulsifies and suspends fat droplets within the watery fluids until what occurs?

*fat-digesting enzymes from the pancreas (lipases) can split them into smaller molecules for absorption (split fatty acids from glycerol backbones...)* [then all the pieces cling in bile balls and go through mucous to waiting intestinal cells... glycerol/short chain fatty acids pass directly thru cells to blood and go to liver un aided. monoglycerides and longer chain fatty acids go into intestinal cells, reform into triglycerides and with protein, form chylomicrons which are lipoproteins that txp them through lymph to blood to liver]

Define fatty acids: Define essential fatty acids

*organic acids composed of carbon chains of various lengths. Each fatty acid has an acid end and hydrogens attached to all of the carbon atoms of the chain* *Essential fatty acids are those the body needs but can't make and so must be obtained from the diet*, including Linoleic (omega 6) and linolenic(omega 3) which serve as raw materials from which the body makes needed products such as eicosanoids which act like hormones and influence many body functions. Note that you need linoleic omega 6 essential fatty acid to make arachidonic acid, and you need linolenic omega 3 fatty acid to make EPA and DHA.

Linoleic and Linolenic refer to..... These are the parents of...

*the two essential polyunsaturated fatty acids discussed in the lecture* ---Linoleic/omega 6/parent of arachidonic acid ----Linolenic/omega 3/parent of EPA/DHA ...........Both linoleic acid and linolenic acid are converted into eicosanoids, bioactive lipids that act like hormones, send signals to body tissue and influence body functions.

the hydrogenation process produces hydrogenated fatty acid when it accepts a hydrogen. The hydrogenation process also produces some ____________

*trans-fatty acids* which retain its double bond but takes a twist and changes its shape instead of becoming fully saturated.

Define monounsaturated fats

*triglycerides in which most of the fatty acids have one point of unsaturation*.........(Ex: olive oil, canola oil, avocado, peanut oil, nuts such as cahews, peanuts)

Define polyunsaturated fats

*triglycerides in which most of the fatty acids have two or more points of unsaturation are poly unsaturated*..............(safflower, most veg oils, walnuts, salmon, shrimp, flaxseed oil)

-bile, an emulsifier made by the _____/stored in the ______, gets released into the ______, where it mixes ______ particles with _______ by ________ them.

-bile, an emulsifier made by the liver/stored in the gallbladder, gets released into the small intestine mixes fat particles with watery fluids by emulsifying them.

When fat gets to the small intestine what happens?

-bile, an emulsifier made by the liver/stored in the gallbladder, gets released into the small intestine -bile mixes fat particles with watery fluids by emulsifying them. -bile emulsifies and suspends fat droplets within the watery fluids until the fat-digesting enzymes from the pancreas (lipases) can split them into smaller molecules for absorption (split fatty acids from glycerol backbones.) -free fatty acids, phospholipids and monoglycerides all cling together in balls surrounded by bile emulsifiers and pass through watery mucous to waiting intestinal cells -glycerol/short chain fatty acids pass through intestinal cells to blood where they go to liver, unaided in txp, then go to tissues that need them -monoglycerides and longer chain fatty acids go into intestinal cell, reform into triglycerides and are packaged w protein into chylomicrons...then travel from small intestine to lymph then to blood and to the liver.

Define monoglycerides

-products of the digestion of lipids -a monoglyceride is a glycerol molecule with one fatty acid attached

How are fats useful in food? (ppt info)

1. Concentrated calories (Lots of energy in small packages) 2. Fat-soluble nutrients (Vitamins: A, D, E, K, /Essential fatty acids) 3. Sensory qualities ( Aromas /Flavors/Tenderness) 4. Satiety ( Slows down food movement )

Dietary factors and their relationship to atherosclerosis and Cardiovascular Heart Disease (CHD) Diets high in each of these has what effect on cholesterol? 1. Dietary cholesterol/saturated fat 2. Trans fatty acid 3. PUFA 4. MUFA 5. soluble fiber 6. physical activity 7. moderate alcohol 8. soy foods 9. sterol/stanol esters

1. Dietary cholesterol/saturated fat: *raises LDL* 2. Trans fatty acid: *raises LDL, lowers HDL* 3. PUFA: *lower LDL, lower HDL* 4. MUFA *lower LDL, no effect on HDL, lower TG?* 5. soluble fiber: *lower LDL* 6. physical activity: *raise HDL* 7. moderate alcohol: *raise HDL* 8. soy foods: *lower LDL* 9. sterol/stanol esters: *lower total cholesterol*

Name the four types of lipoproteins and what they do

1. Very Low Density Lipoprotein: triglycerides/other lipids made in liver-->body cells 2. Low Density: when VLDL dumps triglycerides, now its mostly got cholesterol and has higher % protein so is more dense...LDL carries whats left --> tissues 3. High Density: carries cholesterol away from body cells -->liver for disposal 4. Chylomicron (least dense/more lipids): carries triglycerides from small intestine -->liver (the more lipids, the less dense, the more proteins, the more dense)

Key Point What three main things happen to fat in the small intestine?

1. bile emulsifies the fats 2. enzymes digest them (pancreas secretes lipase) 3. intestinal cells absorb them (i.e absorbs the particles of fatty acids, phospholipids/monoglycerides)

What can I recommend to someone who wants to lower their LDL?

1. eat less saturated fat and trans fat 2. replace this with monounsat and polyunsat fats within a reasonable calorie intake 3. exercise!

Why is fat useful in food?

1. fat is energy dense (concentrated calorie source 9kcal/gram) 2. some essential nutrients are lipid in nature and soluble in fat; some fat in the diet is necessary for their absorption 3. fat has good aroma/flavor, makes food tender 4. fat gives feeling of satiety 5. fat in food slows digestion and helps sustain a feeling of fullness

What would you recommend to someone looking to add omega6 polyunsaturated fatty acids to their diet?

1. non hydrogenated margarine 2. mayo 3. walnuts 4. vegetable oils such as corn, cottonseed, safflower, soybean 5. pumpkin seeds and sunflower seeds

What are the health effects of trans-fatty acids

1. poses risk to heart and arteries by raising blood LDL cholesterol/lowering HDL 2.

Key Point: List 6 reasons why lipids are useful in the body

1. provide and store energy-- 2. cushion vital organs-- 3. insulate against temp extremes-- 4. form cell membranes-- 5. txp fat-soluble substances-- 6. serve as raw materials to make needed stuff

A diet deficient in all of the polyunsaturated fatty acids produces symptoms such as .....

1. reproductive failure 2. skin abnormalities 3. kidney and liver disorders 4. infants: growth retardation/vision impairment

The difference TO HEALTH btw LDL and HDL lies in ____________

1. the proportions of lipids they contain and the tasks they perform...NOT in the type of cholesterol they carry cuz they both carry the same kind. (LDL more lipid filled) 2. *the tasks they perform...bringing fat to tissues vs. to liver*

Limit your cholesterol to less than _____mg per day

300

The Dietary Guidelines recommend choosing __ to __ ounces of a variety of seafood each week, to provide ____ mg EPA and DHA per day

8-12 ounces, or about one of every five protein food servings to provide an avg of 250 mg of EPA and DHA per day.

What is the difference between LDL and HDL?

Both carry lipids in the blood. 1. LDL is larger, lighter and more lipid filled vs. 2. LDL delivers triglycerides and cholesterol from liver to tissues 3. LDL can trigger inflammation, increases rish for CHD 4. LDL= bad cholesterol 1. HDL is smaller and more densely packed 2. HDL takes excess cholesterol and phospholipids from tissues and returns them to liver for disposal (VACUUM ACTION!) 3. HDL reduces rish for CHD 4. HDL = good/Healthy cholesterol

EPA and DHA play important roles in maintaining the health of your _____ by regulating ____ and ____ and reducing ____ and _____ They also play a role in ______ prevention, in cell ________ and in _____ function and ______

EPA and DHA play important roles in maintaining the health of your *heart* by regulating *heart beat* and *blood pressure* and reducing *blood clot formation* and *inflammation* They also play a role in *cancer*prevention, in *cell membrane structure* and in *brain function* and *vision*

The body only makes limited amounts of omega 3 fatty acids such as ____ and ____. BUT, omega 3 fatty acids are found abundantly in ______

EPA/DHA oils of certain fish!

Define EPA, DHA

Eicosapentaenoic acid/Docosahexaenoic acid; omega 3 fatty acids made from linolenic acid in the tissues of fish -play roles in brain communication, disease prevention and human development

Both LDL and HDL carry lipids in the blood, but _____ are larger/ligther/richer in cholesterol. ______ are smaller/denser/packaged with more protein

LDL = larger lighter richer in cholesterol (deliver trig and cholesterol from liver to tissues) HDL are smaller/denser/more protein (takes excess cholesterol/phospholipids and returns them to liver for disposal)

Name the two essential polyunsaturated fatty acids discussed in the lecture

Linoleic (omega 6) Linolenic (omega 3)

What is the difference between a monounsaturated and polyunsaturated fatty acid (PUFA)?

Mono: a fatty acid containing one point of unsaturation (double bonds) Polyunsaturated (PUFA) : a fatty acid with two or more points of unsaturation (double bonds) Note that unsaturated fatty acid = a fatty acid that lacks some hydrogen atoms and has one or more points of un-saturation. An unsaturated fat is a triglyceride that contains one or more unsaturated fatty acids

define glycerol

an organic compound, three carbons long, of interest here because it serves as the backbone for triglycerides

triglycerides are composed of

TRI (three fatty acids) and one GLYCEROL

Define unsaturated fatty acid What is an unsaturated fat?

a fatty acid that lacks some hydrogen atoms and has one or more points of un-saturation (double bonds). An unsaturated fat is a triglyceride that contains one or more unsaturated fatty acids

Define cholesterol:

a member of the group of lipids known as sterols; a soft, waxy substance made in the body for a variety of purposes and also found in animal-derived foods

Why are phospholipids soluble in water?

a phospholipid has a molecule of glycerol with 2 fatty acids and 1 phosphorous attached. phosphorus loves water

Define omega-6 fatty acid

a polyunsaturated fatty acid with its endmost double bond six carbons from the end of the carbon chain, linoleic acid is an example

Define omega-3 fatty acid

a polyunsaturated fatty acid with its endmost double bond three carbons from teh end of the carbon chain. For ex, linolenic acid (essentaial), DHA, EPA are all omega 3 fatty acids.

Define homogenization

a process by which milk fat is evenly dispersed within fluid milk; under high pressure, milk is passed through tiny nozzles to reduce the size of fat droplets and reduce their tendency to cluster and float to the top as cream

Define emulsifier Define emulsification

a substance that mixes with both fat and water and permanently disperses the fat in the water forming an emulsion emulsification is the process of mixing lipid with water by adding an emulsifier

Humans can store energy in specialized cells called

adipocytes, which can be used in times of famine

Define bile...Bile is ______ made by the _____ stored in the _______. Its function is to ____________

an emulsifier made by the liver from cholesterol and stored in the gall bladder. -emulsifiy fat so that enzymes in the watery fluids may contact it and split the fatty acids from their glycerol for absorption

after bile is used in the small intestine to emulsify, what is its fate?

bile may be absorbed, reused or excreted

Key Point Sterols play roles as part of _____, ______, ______ and other important compounds

bile, vitamin D, sex hormones

Define eicosanoids

biologically active compounds that regulate body functions

Lecithin and other phospholipids play an important role in the structure of _______. Explain why

cell membranes...the phospholipid bilayer with its water-loving and fat-loving sides, helps fats travel across the membranes into the watery fluid on both sides

an "atherogenic" diet

diet that is high in saturated fat, including trans fats and low in veggies, fruits, whole grains...it is a risk factor for atherosclerosis /cardiovascular heart disease

Can you change your HDL with diet?

dietary measures are usually ineffective at raising HDL concentration. *regular physical activity is the best way to raise HDL*

Define cardiovascular disease (CVD):

disease of the heart and blood vessels (note that disease of the arteries of the heart is called coronary heart disease, CHD)

Fat cells respond to the call for energy by___________

dismantling stored fat molecules (triglycerides) and releasing fatty acids into the blood. (energy hungry cells break down fatty acids into fragments and combine each fragment with a glucose fragment, liberating energy, CO2 and water)

What happens to fat in the stomach?

droplets of fat separate from watery components and float as a layer on top.

Which foods contain cholesterol? eggs, peanuts, shrimp, lamb, chocolate cake, whole grain bread, brown rice, avocado, liver, corn oil, OJ, beef, broccoli, black beans, pasta, apples, low fat yogurt, palm oil

eggs, shrimp, lamb, choc cake, liver, beef, low fat yogurt if it has a liver, it has cholesterol...and if it was made with eggs like choc cake/home made pasta

Key Point Linoleic acid and linolenic acid are converted into ________ which influence diverse body functions

eicosanoids

How is fat broken down to provide cellular energy?

fat fragments broken down and combine with fragments of glucose from glycolysis, and yield energy, CO2 and H2O (this is why if you don't have carbs, you have ketones which are products of incomplete fat break down)

Which essential nutrients are lipid in nature?

fat soluble vitamins A, D, E, K fatty acids......including essential fatty acids: Linoleic (omega 6) and Linolenic (omega 3)

Define fats: Define oils:

fats = lipids that are solid at room temp (70F/21C) oils: lipids that are liquid at room temp

Define Solid Fats

fats that are high in sat fatty acids and are usually solid at room temp. Found naturally in most animal foods but also can be made from veg oils thru hydrogenation

_______ chains of carbons; chains can be of varying lengths

fatty acid

Define trans-fatty acids

fatty acids with unusual shapes that can arise when hydrogens are added to the unsaturated fatty acids of polyunsaturated oils (a process known as hydrogenation)

What would you recommend to someone looking to increase their intake of omega 3 polyunsaturated fats?

fatty fish, flaxseed, nuts

_______ is a water soluble carb derivative; made of 3 carbons

glycerol

from the small intestine, ______ and ______ can pass directly through the cells into the bloodstream; they travel to the liver, unaided in txp and to the tissues that need them

glycerol and short chain fatty acids.

______ and ________ pass directly through the cells of the intestinal lining into the blood stream where they travel unassisted to the liver and to the tissues that need them

glycerol and shorter-chain fatty acids

Key Point ______ and ________ travel in the blood stream unassisted. other lipids need special txp vehicles called ______

glycerol/short chain fatty acids. lipoproteins

Why is storing fat more efficient than storing glycogen?

glycogen holds a great deal of water, so it is bulky and heavy and the body can't store enough to provide energy for a long time fats pack tightly together withotu water and can store more energy in a small space; gram for gram fats provide more than twice the energy of carbs or protein.

High blood LDL and low HDL are major risk factors for

heart disease

HDL

high density lipoproteins are critical in the processing of carrying cholesterol away from body cells to the liver for disposal (the more lipids, the less dense, the more proteins, the more dense)

What is so great about the Mediterranean diet?

high in unsaturated fat low in saturated fat

The number one dietary determinant of LDL is...

how much saturated fat you have in your diet.

What are good sources of EPA and DHA

human milk, fish and seafood

The process of ________ creates trans-fatty acids

hydrogenation

Where is cholesterol produced and why?

in the liver because its the raw material for making bile

Sterols are complicated molecules consisting of

interconnecting rings of carbon atoms with side chains of C, H and O2 attached

What do the Dietary Guidelines for Americans 2010 say about trans fats?

keep trans fat intake as low as possible by limiting foods that contain synthetic sources of trans fats such as partially hydrogenated oils and by limiting other solid fats

When fat and cho burn together it prevents

ketosis!

after lipases split fat into smaller particles for absorption in the small intestine, what is left? What happens to the stuff that is left?

leftovers: *glycerol, fatty acids, phospholipids, monoglycerides* What happens to these? *they cling together in balls surrounded by bile and are shuttled across the watery layer of mucous of the absorptive cells of the intestinal villi* the small stuff passes thru to blood, the big stuff enters the cell reforms triglycerides, meets up with protein and forms lipoprotein (chylomicron) then together goes into lymph then blood then to liver

parent member of omega-6 fatty acid family

linoleic acid

Define linoleic and linolenic acids

linoleic acid = an essential polyunsaturated fatty acid of the omega-6 family linoleNic acid = an essential polyunsaturated fatty acid of the omega 3 family.

________ is the parent member of the omega 3 fatty acid family

linolenic

When LDL cholesterol is too high, it contributes to...

lipid buildup in tissues, particularly in the linings of the arteries, that can trigger inflammation and lead to heart disease

Key Point: Lipids provide abundant _________ in a small package, enhance _______ and _______ of foods and contribute to feelings of ________

lipids provide abundant food energy in a small package, enhance aromas and flavors of foods, and contribute to satiety.

Define chylomicrons

lipo-proteins formed when lipids form a meal cluster with carrier proteins in the cells of the intestinal lining -txp food fats (mainly triglycerides) through the watery fluids to the liver and other tissues.

In the blood stream, fat travels as passengers on _______

lipoproteins

packages of lipid and protein molecules

lipoproteins, ex, chylomicron

LDL

low density lipoproteins transport cholesterol and other lipids to the tissues. LDL is made from VLDL after they have donated many of their triglycerides to body cells (the more lipids, the less dense, the more proteins, the more dense)

Define phospholipids and also say where you might find them

one of the three main classes of dietary lipids. These are similar to triglycerides, but each has a phosphorus-containing acid in place of one of the fatty acids; present in all cell membranes.

how do glycerol and shorter chain fatty acids make their way out of the small intestine and where do they go from there?

pass directly through the cells of the intestinal lining into the blood stream where they travel unassisted to the liver and to the tissues that need them

What is the predominant type of fat (triglyceride) found in the following foods? Which foods are likely to contain trans-fat?*walnuts*

polyunsaturated (walnuts are an exception...most nuts/seeds are monounsaturated. walnuts are high in omega 6 PUFA)

What is the predominant type of fat (triglyceride) found in the following foods? Which foods are likely to contain trans-fat? *salmon*

polyunsaturated fat

lipoproteins are clusters of _______ and ________ that act as emulsifiers, attracting both water and fat to enable their large lipid passengers to travel dispersed in the watery body fluids

protein and phospholipids

What are good food sources of linoleic acid?

seeds, nuts, vegetable oils (corn/cottonseed/safflower/sesame/soybean/sunflower) poultry fat

The body makes four main types of lipoproteins, distinguished by their_____ and ______. the four include:

size/density (the more lipids, the less dense, the more proteins, the more dense) 1. Very Low Density Lipoprotein: triglycerides/other lipids made in liver-->body cells 2. Low Density: when VLDL dumps triglycerides, now its mostly got cholesterol and has higher % protein so is more dense...LDL carries whats left --> tissues 3. High Density: carries cholesterol away from body cells -->liver for disposal 4. Chylomicron (least dense/more lipids): carries triglycerides from small intestine -->liver

Why would margarine be perceived as being better than butter?

soft or liquid margarine is made from unhydrogenated oils, which are mostly unsaturated and thus thought to be less likely to elevate blood cholesterol than more saturated solid fats of butter or stick margarine

What is the predominant type of fat (triglyceride) found in the following foods? Which foods are likely to contain trans-fat? *margarine*

some mono or poly and TRANS fat

Name the class of lipid that includes bile

sterol! cholesterol is another example.

complicated molecules consisting of interconnecting rings of carbon atoms with side chains of C, H, and O2 attached

sterols

Key Point Fats separate from other food components in the ________

stomach

How can you reduce your LDL cholesterol?

sub saturated fat w mono and poly unsat fat

Key Point What determines how soft or hard fat is?

the degree of saturation of the fatty acids. The more saturated the more solid

Why doesn't mayonnaise separate into its vinegar and oil like salad dressing?

the egg yolks have an emulsifier, lecithin, a phospholipid which keeps fats dispersed in water, and blends the vinegar with the oil to form the stable, spreadable mayo

What determines if fat is solid or liquid at room temp? Which type of fat is solid at room temp?

the more unsaturated the fat the more liquid it is at room temp. saturated fat is solid

Define hydrogenation

the process of adding hydrogen to unsaturated fatty acids to make fat more solid and resistant to the chemical change of oxidation (i.e. makes them stay fresher longer while changing their physical properties)

Key Point What does the body combine to make a triglyceride, the storage form of fat?

three fatty acids with one glycerol

Key Point: To lower LDL in the blood..... To increase HDL....

to lower LDL follow a healthy eating pattern that replaces dietary sat fat and trans fat w polyunsaturated/monounsaturated oils to raise HDL be physically active

Name the class of lipid that is 96% of what we eat and is what we store in our adipocytes

triglycerides

The lipids in foods and in the human body generally fall into three classes:

triglycerides (95%) phospholipids (for ex, lecithin) sterols (for ex, cholesterol)

Define Saturated Fats

triglycerides in which most of the fatty acids are saturated

the term fat generally refers to

triglycerides, the major form of lipid found in food and in the body

Saturation refers to

weather or not a fatty acid chain is holding all of the hydrogen atoms it can hold