Chapter 6: Lipids Flashcards
define: lipids
lipids: molecules that are partly or entirely hydrophobic
What are the different types of lipids (4)?
Types of lipids: triglycerides, fatty acids (fats), sterols, and phospholipids
define: triglycerides
Triglycerides: main dietary lipid; consist of a glycerol backbone with 3 fatty acids attached to it
define: saturated fatty acids
Saturated fatty acids: no double bonds and saturated with h bonds
define: unsaturated fatty acids
Unsaturated fatty acids: 1 or more double bonds (mono/poly)
fill in the blank ____ fats are solid at room temperature and ____ fats are liquid at room temperature
saturated; unsaturated
What foods have saturated fats?
animal products
What risk does saturated fatty acids come with?
Longer chains of saturated fatty acids are more common in animal foods and increase CVD risk → increases LDLs
What type of saturated fats may promote weight loss. Why?
Medium chains of saturated fatty acids are found in tropical oils and easier to digest/absorb; They go directly into the blood, bypassing lymph and peripheral tissues, less likely to be deposited as body fat.
What foods have unsaturated fats?
plant based foods
Define: monounsaturated fats;
Monounsaturated fats: one double bond
Define: polyunsaturated fats
Polyunsaturated fats: 2+ double bonds
Define: essential fatty acids
Essential fatty acids: polyunsaturated fatty acid with a double bond before the 9th position
What are 2 essential fatty acids?
omega-3 and omega-6
Examples of foods with omega-3
- alpha-linolenic acid: chia and flax seeds
- DHA and EPA example: milk, fish, beef, lamb
Fill in the blank: alpha-linolenic acid can be used to synthesize 2 other omega-3 fatty acidS: ____ and ___
DHA and EPA
Sources of omega-6
soybeans, corn, vegetable oils
fill in the blank: Linoleic acid can be used to synthesize another omega-6 fatty acid called _____
arachidonic acid
Functions of essential fatty acids (3)
- Important for formation of phospholipid bilayer of cell membrane (and therefore important for growth, skin integrity, fertility, red blood cell structure)
- Arachidonic acid and DHA are essential for normal brain development in infants and young children
- Longer chain omega-6s and omega-3s help form eicosanoids
Fill in the blank: Both omega-6 and omega-3 fatty acids can be used to synthesize _____
eicosanoids
define: eicosanoids
Eicosanoids: signalling molecules (hormone-like)
What are eicosanoids associated with?
overall: decreased risk of heart disease
- Reduced inflammation
- Vasodilation
- Inhibition of blood clotting
- Lower blood cholesterol
What are some signs of essential fatty acid deficiency (5)
- Dry scaly skin
- Liver abnormalities
- Poor healing
- Impaired vision
- Growth failure in infants
Sources of fatty acids by length
- long
- medium
- short
- Long chains are found in a variety of animal products and some plants
- Medium chain fatty acids are found in tropical oils
- Short chain fatty acids are made by bacteria when they ferment indigestible carbs in our large intestine