Chapter 6- The Lipids Flashcards
What are the four primary classes of lipids ?
- fatty acids
- triglycerides
- sterols
- phospholipids
Lipids contain ___________, _____________, and ___________.
Carbon; hydrogen; oxygen
Lipids are a component of _______________.
Cell membranes
Lipids are the primary source of the body’s energy reserves, which are stored in the _________.
Adipose tissue
Fats contribute to the sensation of being full because…
- fats stay in the stomach longer
* fats are absorbed over a longer period of time
Fatty acids
Major source of energy
Triglycerides
MOST abundant source of fat in our body!
Sterols
Cholesterol is the primary dietary sterol
Phospholipids
The primary lipid in the cell membrane
What are triglycerides commonly called?
Fat, they are essential!
What is the basic structure of a triglyceride?
Three-carbon glycerol molecule with 3 fatty acids attached
Saturated Fatty Acids
They are fully hydrogenated, all carbons are “saturated” with hydrogen, and there are NO double bonds.
Example of a saturated fatty acid?
(Tend to be solid at room temperature)
- animal origin (aka butter)
- tropical oils
Unsaturated Fatty Acids
Fewer hydrogen atoms, contain one or more double bond
Example of unsaturated fatty acid?
Tend to be liquid at room temperature, aka olive oil.
Monounsaturated vs Polyunsaturated fatty acids ?
Mono: one double band of point of unsaturation
Source: avocado, peanuts, almonds
Poly: more than one double bond
Source: mostly vegetable oils
Partial Hydrogenation creates fatty acids
Adding hydrogen to an unsaturated fat can alter the position of the double bonds
What can Trans Fatty Acids do?
- Raise “bad” cholesterol and lower “good cholesterol”
* Increase risk of heart disease
How can I identify if a product contains Trans fat?
Check for partially hydrogenated oil in the ingredients list
What are essential fatty acids that must be supplied through the diet?
- omega-6 fatty acids (Linoleic acid)
* omega-3 fatty acid (Linolenic acid)
What is Omega-6 fatty acid- Linoleic acid essential for?
•growth and synthesis of hormone-like compounds (ercasonoids)
Source of omega-6?
FISH
What is Omega-3 Fatty acid for?
Helps elevate HDL levels, and helps regulate blood pressure and clotting
Omega-3 Source?
Flaxseed; flaxseed oil; chia seeds, hemp seeds, cauliflower, brusselsprouts
Phospholipids can be produced by ________.
The body
A Phospholipids unique structural arrangement allows them to…
Suspend fat in water
What is the structure of a phospholipid?
3 carbon glycerol molecule with 2 fatty acids and a phosphate group on the third carbon
Phospholipids are the primary components of ________.
cell membranes
What phospholipid is found in egg yolks that is also an emulsifier?
Lecithin
Where does most of the lipid digestion occur?
The small intestine, and a small amount in the mouth and stomach by lipase
Digestion in the small intestine is facilitated by…
•bile acids, emulsification, lipases
How does emulsification aid in digestion?
It allows fat to mix with water
Lipids do NOT
Travel freely in the the blood
What are sterols?
Complex lipids
What is the structure of a sterol?
Sterols have four interconnected carbon rings with and oxygen and a hydrocarbon side chain
What is a nonessential sterol that the liver produces?
Cholesterol
Cholesterol is only found in _____________.
Animal foods
Cholesterol is a critical component of cell membranes therefore it is found in ____________________.
Every cell in our body, it also does not provide calories!
AMDR of total fat ?
Between 20% to 35% of total calories
What are chylomicrons?
Transport dietary fats and cholesterol from intestines to muscle and adipose tissue
VLDL
Carries mainly triglycerides from liver to muscle and adipose tissue
LDL
VLDL is converted into LDL which carries primary cholesterol to all cells in the body
AKA BAD CHOLESTEROL
HDL
Picks up cholesterol from the body cells and returns to the liver
AKA GOOD CHOLESTEROL
