59 lines
2.6 KiB
Markdown
59 lines
2.6 KiB
Markdown
- **Lipids** are a class of nutrients that do not dissolve in water.
|
|
- They will dissolve in organic solvents
|
|
- Oil is less dense than water, so it will rise to the top of a solution
|
|
- Major functions of lipids in the body include
|
|
- Providing and storing energy
|
|
- forming and maintaining cell membranes
|
|
- producing steroid hormones
|
|
- insulating the body
|
|
- cushioning the body against bumps and blows
|
|
- forming body contours
|
|
- **absorbing fat soluble vitamins and phytochemicals**
|
|
## Fatty Acids
|
|
A fatty acid is a hydrocarbon chain found in lipids; one end of the chain forms a carboxylic acid, and one end forms a methyl group.
|
|
- Short chain fatty acids have 2 to 4 carbons
|
|
- Medium chain fatty acids have 6 to 12 acids
|
|
- Long chan acids have 14 to 24 carbons
|
|
- Fatty acids are identified by:
|
|
- The number of carbon atoms
|
|
- The type of bond between carbon atoms
|
|
|
|
- **Saturated fatty acid (SFA)** Every single carbon atom is filled with hydrogen atoms
|
|
- **Unsaturated fatty acid** is a fatty acid that is missing hydrogen atoms and has one or more double bonds within the carbon chain
|
|
- **Monounsaturated** (MUFA)
|
|
- Has one double bond within the carbon chain
|
|
- Sources include:
|
|
- **Canola oil**
|
|
- **Olive oil**
|
|
- **Avacados**
|
|
- Nuts
|
|
- Seeds
|
|
- Peanut butter
|
|
- **Polyunsaturated** (PUFA)
|
|
- Fatty acid that has two or more bonds within the carbon chain
|
|
- Sources include:
|
|
- **Soybean oil**
|
|
- **Fatty fish**
|
|
- **Flax seed**
|
|
- **Walnuts**
|
|
- Corn oil
|
|
- Sunflower oil
|
|
- Most naturally occurring fatty acids are cis fatty acids
|
|
- Hydrogen atoms of the double bonded carbon are on the same side of the hydrocarbon atom
|
|
- **Trans fats** are unsaturated fatty acids that have a trans double bond.
|
|
- Hydrogen atoms of the double bonded carbons are on the opposite side of the hydrocarbon chain
|
|
- **Hydrogenation** is the food manufacturing process that adds hydrogen atoms to liquid vegetable oil, forming trans fats.
|
|
- Can be stored for longer periods because they are less likely to undergo oxidation
|
|
- Raise "bad" cholesterol levels in the blood
|
|
- Increases risk of heart disease
|
|
- **Essential fatty acids** are fatty acids that must be supplied by the diet
|
|
- **Linoleic acid** - 18 carbon omega-6 fatty acid found in vegetable oils
|
|
- **Alpha-linolenic acid** - 18 carbon omega-3 fatty acid, found in flaxseed, walnuts
|
|
- Precursor for
|
|
- Eicosapentaonoic acid (EPA) - 20 carbons
|
|
- Docosahexaenoic acid (DHA): 22 carbons
|
|
- Both acids are found mainly in fatty fish
|
|
- Essential fatty acids are needed for growth and healthy cell membranes, especially in the brain.
|
|
# Triglycerides
|
|
# Phospholipids
|
|
# Sterols |