4. Lipids

Question 1

What are the common properties of lipids?

Answer 1

• Lipids do not readily dissolve in water
• Yield 9 kcal per gram
• Fats (solid) and oils (liquid)

Question 2

Define triglyceride.

Answer 2

3 fatty acids bonded to glycerol.

Question 3

What is a fatty acid?

Answer 3

Long chain of carbons bonded together.

Alpha end (carboxylic acid group - COOH)

Omega end (methyl group - CH3)

Functions:

• form body structures
• perform important functions for the immune and nervous system
• produce regulatory compounds

Question 4

Define phospholipid.

Answer 4

• Glycerol + 2 fatty acids+ phosphorus-containing compound
• synthesized by the body as needed
• component of cell membrane
• play a role in digestion, absorption, and transport of lipids

Question 5

Define sterols.

Answer 5

• multi-ringed structure
• cholesterol (found only in foods of animal origin)
• phytosterols (found in foods of plant origin)

Question 6

Importance of essential fatty acid

Answer 6

When the essential fatty acids are consumed, the body can use them to make other, nonessential fatty acids. These eventually give rise to a variety of eicosanoids that regulate body functions.

Question 7

Describe a Cis fatty acid.

Answer 7

The hydrogens that flank the carbon-carbon double bond lie on the same side.

Question 8

Describe a Trans fatty acid.

Answer 8

The hydrogens that flank on a double bond lie on opposite sides of the double bond.

Question 9

What are some food sources of essential fatty acids?

Answer 9

• Safflower oil
• Sunflower oil
• Nuts and seeds
• Chicken
• Flaxseeds
• Walnuts
• Chia seel oil

Question 10

What are some food sources of phospholipids?

Answer 10

• Wheat germ
• Peanuts
• Egg yolk
• Soybeans
• Organ meats

Question 11

What are some food sources of sterols?

Answer 11

• Eggs
• Meats
• Whole milk

Question 12

What are some food courses of saturated fatty acids?

Answer 12

• Coconut oil
• Butter
• Palm oil
• Lard or beef fat

Question 13

What are some food sources of monounsaturated fatty acids?

Answer 13

• Olive oil
• Canola oil
• Peanut oil

Question 14

What are some food sources of polyunsaturated fatty acids?

Answer 14

• Safflower oil
• Sunflower oil
• Corn oil
• Soybean oil

Question 15

What are the 4 lipoproteins?

Answer 15

1. Chylomicron
2. Very-low density lipoprotein (VLDL)
3. Low-density lipoprotein (LDL)
4. High-density lipoprotein (HDL)

Question 16

What is the main function of chylomicrons?

Answer 16

Primary component: triglyceride

Function: carries dietary fat from the small intestine to cells

Question 17

What is the primary function of VLDL?

Answer 17

Primary component: triglyceride

Function: carries lipids made and taken up by liver to cells

Question 18

What is the primary function of LDL?

Answer 18

“bad cholesterol”

Primary component: cholesterol

Function: carries cholesterol made by the liver and from other sources to cells

Question 19

What is the primary function of HDL?

Answer 19

“good cholesterol”

Primary component: protein

Function: contributes to cholesterol removal from cells and, in turn excretion of it from the body

Question 20

Describe the functions of the various forms of lipids in the body.

Answer 20

1. Provide energy
2. Structural components
3. Regulate cellular processes

Question 21

What are the current recommendations for fat intake?

Answer 21

Total fat: no RDA for total fat intake for adults

Acceptable macronutrient distribution range:

• 20-35% for kcal from fat
• 44-78 grams for 2000 kcal

Question 22

What are double bonded and on the long chain of the bond

Answer 22

Omega 3 and Omega 6 fatty acids