Lipids

Question 1

What are the types of Lipids?

Answer 1

• Fatty Acids: Most basic form of lipids

-Triglycerides: are the main form of lipids in food and body. Eg olive oil

• Phospholipids eg. Bile

-Sterols eg. Cholesterol

Question 2

What are the 3 properties of Lipids

Answer 2

Mostly made of fats and oils

Do not readily dissolve in water

Energy dense 9kcal/g

Question 3

Fat vs Oil

Answer 3

⚫ Fats are solid at room temperature

⚫ Oils are liquid at room temperature

Question 4

What are some functions of lipids?

Answer 4

Provide energy

Efficient storage of energy

Protection

Transport fat-soluble vitamins

Question 5

Describe the Fatty Acid Structure

Answer 5

H
- Omega end: H-C
H

• degree of saturation: single/double carbon bonds
• Alpha end: H O
  | ||
  C - C- OH
  |
  H

Question 6

Monounsaturated Fatty Acid Structure

Answer 6

Omega end + double carbon bond in centre + alpha end

Question 7

Polyunsaturated Fatty Acid structure

Answer 7

Omega end

2 double bonds
Alpha end (in center and bonded togetehr by a single carbon bond)

Alpha end

Question 8

Essential Fatty Acids

Answer 8

• Body can only make double bonds
  starting from the 9th carbon from
  the omega end

-Needed for immune function,
vision, cell membrane, and
production of hormone-like
compounds

Question 9

Essential Fatty Acid- Omega-3

Answer 9

(alpha-linolenic acid)

Omega end

1st double bond located on the 3rd carbon from the omega end

Alpha end

Question 10

Saturated vs Unsaturated Fat

Answer 10

Saturated: Single carbon bonds

Unsaturated: double carbon bonds

Question 11

Sources of Omega 3

Answer 11

-Primarily from fish oil

-Also found in canola or soybean oil

Recommend intake of ~2 servings of
fish per week

Question 12

Essential Fatty Acid- Omega-6

Answer 12

(Linoleic acid)

Omega end

• 1st double bond is located on the 6th carbon
  from the omega end

Alpha end

Question 13

Sources of Omega-6 Fatty Acid

Answer 13

-Found in vegetable oils

-Only need
~ 1 tablespoon a day

Question 14

Rich sources of Saturated fatty Acids

Answer 14

Coconut oil
Butter
Palm oil
Lard/ beef fat

Question 15

Rich sources of Monounsaturated Fatty acids

Answer 15

Olive oil
Canola Oil
Peanut Oil
Soybean oil

Question 16

Rich sources of Polyunsaturated Fatty Acids

Answer 16

Safflower Oil
Sunflower Oil
Corn Oil

Question 17

Trans fatty Acids

Answer 17

Tub margarine
Stick margarine
Shortening

Question 18

Triglycerides chemical structure

Answer 18

• Fatty Acid
  Glycerol Backbone- Fatty Acid
  - Fatty Acid

Question 19

Phospholipids

Answer 19

• Built on a glycerol backbone
• Has at least one fatty acid replaced with
  phosphorus compound

Fatty Acid-
Fatty Acid- Glycerol- phosphate-Alchohol

• Synthesized by the body as needed

Question 20

Functions of
Phospholipids

Answer 20

• Make up cell membrane
• Emulsifier
  ⚫ Bile acids
  ⚫ Lecithins
  ⚫ Improves food products

Question 21

What is an emulsifier?

Answer 21

A compound that can suspend fat in water by isolating individual fat droplets with water molecules/substances to prevent fat from coming together.

(If the fat comes together, it will rise to the top)

Question 22

Sterol

Answer 22

Cholesterol

-Do not have a glycerol backbone

-Waxy substance

-Does not readily dissolve in water

Question 23

Functions of Cholesterol

Answer 23

Essential component of cell
membrane

Produced by the liver

Found only in animal products

Forms important hormones
⚫ Estrogen, testosterone, vitamin D

Component of bile

Question 24

Characteristics of Reduced-fat foods

Answer 24

Total energy is about the same

Sugar is commonly added in place of fat

Question 25

Digestion of Fat in Stomach

Answer 25

Triglyceride: glycerol + 3 fatty acids Diglyceride: glycerol + 2 fatty acids Monoglyceride: glycerol + 1 fatty acid Gastric lipase works only in an acidic environment Gastric lipase acts on triglycerides containing short & medium chain fatty acids Longer fatty acid chain is not affected by the stomach acid

Question 26

Digestion of Fat in Small Intestine

Answer 26

-Primary site of fat digestion -Pancreas releases pancreatic lipase -Bile acid emulsifies digested fat -Fat is broken down to monoglycerides and fatty acids

Question 27

Absorption of Fat

Answer 27

Diffuse into the absorptive cells Short and medium chain (<12 C) fatty acids are water soluble ⚫ Enters the portal system Long chain fatty acids reforms into TG ⚫ Enters the lymphatic system

Question 28

High Density Lipoprotein (HDL)

Answer 28

-Synthesized by liver and intestine -Picks up cholesterol from different parts of the body and takes it back to the liver

Question 29

Benefits of (a high) HDL (level)

Answer 29

Remove cholesterol from the blood stream Reduce risk of heart disease

Question 30

Hydrogenation of Fatty Acids

Answer 30

-Process used to solidify an oil -Addition of H to C=C double bonds -Increases shelf life -Formation of trans fatty acid (similar to shape of saturated fatty acid)

Question 31

Health Dangers of Excessive Trans Fatty Acid

Answer 31

Raises LDL Lowers HDL Increases risk for heart disease

Question 32

Minimize Intake of Trans Fatty Acid

Answer 32

Limit use of hydrogenated fats Limit deep-fried foods Limit high fat baked goods Limit use of non-dairy creamers

Question 33

Heart health and Fat- The American Heart Association

Answer 33

For high risk individuals: <20-30% of total kcal from fat/day <7-10% from saturated fat (includes trans fatty acid) <200-300 mg cholesterol a day

Question 34

The National Cholesterol Education Program states that:

Answer 34

Reduce saturated fat intake to 7% of total energy Reduce cholesterol to 200 mg/day Eat diet with plenty of fruits and vegetables Cut down on red meats Cut down on simple sugars and refined CHO

Question 35

Cardiovascular Disease

Answer 35

Symptoms take years to develop Plaque build-up can begin in childhood Atherosclerosis = buildup of fatty plaque in the arteries ⚫ Angioplasty = surgical treatment to widen the affected artery and allow blood to flow more freely Myocardial infarction (heart attack)

Question 36

The Road to a Heart Attack

Answer 36

-Gradual build up of plaque in arteries - Arteries become so block it forms a clot -Clot in arteries leading to heart causes a heart attack

Question 37

Risk Factors for Heart Disease

Answer 37

Family history Smoking (even second hand) High blood pressure High blood cholesterol (hyperlipidemia) ⚫ >200 mg/dl of total cholesterol ⚫ HDL < 40 mg/dl Diabetes Lack of regular exercise and obesity

Question 38

Reducing Your Risks- Primary Prevention

Answer 38

Reduce dietary saturated fat and cholesterol (red meat) Increase MUFA and PUFA to recommended amounts Increase dietary fiber Increase activity; develop a exercise routine Adequate caloric intake to maintain healthy weight

Question 39

Lowering LDLs

Answer 39

LDL linked to cardiovascular disease Reduce dietary saturated fat, trans fat and cholesterol Increase MUFA and PUFA Increase dietary fibre (soluble)

Question 40

Lowering Blood TG

Answer 40

Is the most diet-responsive blood lipid Don’t Overeat Limit alcohol Limit simple sugars Include small frequent meals Include fish in the diet

Question 41

Raise the HDL

Answer 41

Physical activity At least 45 min./day, 4 days a week Avoid smoking Eat regularly Eat less total fat