General Ch. 5: Lipids Flashcards
3 types of lipids
Triglycerides
Phospholipids
Sterols
Are lipids hydrophilic or hydrophobic?
Hydrophobic
What three elements do lipids have?
Carbon, oxygen, hydrogen
What are the building blocks for triglycerides and phospholipids?
fatty acids
How many carbons comprise a short fatty acid chain?
up to 8
How many carbons comprise a medium fatty acid chain?
8-12 carbons
How many carbons comprise a long fatty acid chain?
12+
What determines the degree of saturation of a fatty acid?
The existence of a single or double bond
Which type of fatty acid has no double bonds?
Saturated
Which type of fatty acid has one or more double bond?
Unsaturated
Where is the double bond located on an Omega-3 fatty acid?
between 3-4th carbons from the omega end
Where is the double bond located on an Omega-6 fatty acid?
Between the 6-7th carbons from the omega end
What are essential fatty acids defined as?
Fatty acids that must be supplied by the diet
What are two examples of essential fatty acids?
Linoleic acid
Alpha-linolenic acid
What are the two notation systems from fatty acid?
Delta: chain length, number/position of double bonds from carboxl end
Omega: position of double bonds counted from omega end of chain
What is the spoiling of fats through oxidation?
Rancidity
What type of fats become rancid before the other type?
Unsaturated fats become rancid before saturated fats
What are the three ways to enhance stability of fatty acids and reduce rancidity?
- Adding antioxidants
-Limiting exposure to oxygen, heat, light
-Hydrogenation
What lipid makes up about 95% of lipids found in food?
Triglycerides
What makes up a phospholipid?
Glycerol backbone
2 Fatty acids
Phosphate group
Nitrogen-containing compounds
What type of phospholipid is used as an emulsifier in foods/salad dressings?
Lecithin
What makes up a sterol?
4 connecting rings of carbon/hydrogen
What is the best known sterol?
Cholesterol
What are two major plant sterols?
Phytosterols
Phytostanols
What are the enzymes that digest lipids?
Lipases
What is the enzyme in the mouth that begins the digestion of lipids?
Lingual Lipase
What hormone in the stomach stimulates the release of gastric lipases?
Gastrin
What enzyme digests phospholipids?
Phospholipase
Which type of lipid isn’t digested, carried intact through the intestinal wall, and emulsified by bile?
Sterols
Which lipids are absorbed directly into the bloodstream, into hepatic portal vein, and to the liver?
Glycerol and short/medium fatty acid chains
Which lipids are combine with phospholipids/cholesterol to form chylomicrons and go through the lymph system?
Long-chain fatty acids
Which lipoprotein is 90% triglycerides?
chylomicron
Which liproprotein is 60% triglycerides?
VLDL
Which lipoprotein is 50% cholesterol?
LDL
Which lipoprotein is 50% protein?
HDL
Which lipoprotein transports triglycerides and cholesterol from liver to cells?
VLDL
Which lipoprotein carries cholesterol from liver to tissues?
LDL
(lousy) raises blood cholesterol
Which lipoprotein carries cholesterol from the cells to the liver?
HDL
(healthy) lowers blood cholesterol
What is the AMDR recommendation for fat?
20-35% of daily kcals
3 categories of fat substitutes
Carb-based
Protein-based
Fat-based
What is the narrowing of coronary arteries due to the build-up or debris along artery walls?
Atherosclerosis
