Ch. 5 Lipids

Question 1

Describe four classes of lipids

Answer 1

Fatty acids (major energy source)
Triglycerides (most abundant and storage form of fat)
Sterols (cholesterol)
Phospholipids (in cell membrane)

Question 2

Functions of fats in body

Answer 2

Metabolized for energy
Make hormones like compounds
Fat protects body from extreme temperatures
Carries fat soluble vitamins

Question 3

Saturated fatty acids

Answer 3

• Type of fatty acid
• Carbon atoms have every available bond filled with hydrogen
• Solid at room temp.

Question 4

Monounsaturated fatty acid

Answer 4

• One double bond or point of unsaturation in carbon chain

- Plant sources and some nuts like peanuts and almonds

Question 5

Polyunsaturated fatty acids

Answer 5

More than one point of unsaturation or more than one double bond

Most vege oils

Question 6

Phospholipids

Answer 6

Three carbon glycerol molecule with two fatty acids and a phosphate group on the third carbon

• required for the transport of other lipids in the blood

Question 7

Define sterols

Answer 7

Complex lipid with four carbon rings and a hydrocarbon side chain

Cholesterol is the most common lipid

Question 8

Cholesterol

Answer 8

Produced by the liver and obtained from food

Critical for cell membranes and needed to help produce bile, vitamin d, estrogen and testosterone

Question 9

Organs involved in lipid digestion

Answer 9

Salivary glands
Stomach
Liver (bile)
Gallbladder (stores bile)
Pancreas (releases enzymes) 
Small intestines

Question 10

Food sources of cholesterol

Answer 10

HDL: olive oil, beans and legumes, whole grains, high fiber fruits

LDL: Beef, lamb, butter, cream, milk

Question 11

Essential fatty acids

Answer 11

Omega 6 - linoleic
omega 3 - linolenic

They become EPA and DHA

Helps with inflammation, reduces heart disease

Question 12

Describe lipid digestion and absorption (6 steps)

Answer 12

1. Bile acids produced by liver attach to lipid globules
2. Lipids are suspended in water and dispersed into smaller droplets
3. Pancreatic lipase digests the triglycerides to monoglycerides and fatty acids
4. Digest lipids and bile are packaged into micelles
5. Lipids leave the micelle and are absorbed by transporters
6. Lipids are repackaged by the cell into chylomicron

Question 13

Lipoproteins

Answer 13

Classified by their density and function

Includes chylomicron, HDL and LDL

Question 14

define chylomicrons

Answer 14

• Lipoproteins made in intestinal cells or enterocytes

- Transports fat from the intestines to the body

Question 15

Define LDL

Answer 15

• Low density lipoprotein
• Made in liver
• Transports cholesterol from liver to the cells of the body
  You want LDL to be low

Question 16

Define HDL

Answer 16

High density lipoprotein

Collects fat and cholesterol from the body to transport back to liver

Question 17

Recommended fat intakes

Answer 17

• Fat: 20-35%
• Most fats should come from unsaturated sources
• Less than 10% saturated fats

Question 18

Methods to reduce fat intake

Answer 18

• Grill or oven bake instead of pan frying
• Select lean cuts of meat
• cut down on sauces and toppings
• Remove skin and fat from meats

Question 19

Calories per gram of fat

Answer 19

9 cals