Lipids Flashcards
Fat composed of
Carbon
Hydrogen
Oxygen
Role of fats in the body
- Essential for life
- Functional and structural integrity of a cell membrane
- Insulation
- Large energy source
Fatty acids
4-24 carbons long, with the 18 carbon ones being the most common in foods
Short chain fats
Fewer than 6 carbons
Medium chain fats
6-12/14 carbons
Long chain fats
14-24 carbons
Saturated fatty acids
Molecule is fully loaded with hydrogen atoms
Monounsaturated fatty acid ratio (C:double bonds)
16:1
Polyunsaturated fatty acid ratio (C:double bonds)
16:2
Location of the double bond
Unsaturated fatty acids are identified by the position of the double bond closest to the methyl group —> omega group
Triglycerides description
1 glycerol + 3 attached fatty acids
Role of triglycerides
- Provides energy
- Insulator
- Spare protein
Phospholipids
Found naturally or added to foods; a component of cell membranes
Sterols
- Found naturally in foods
- 4 ring structure
- Structural role membranes
3 ways manufacturers can protect fat containing products against rancidity
- Sealed airtight and refrigerated
- Add antioxidants
- Hydrogenation
Hydrogenation of fats
Manufacturers add hydrogen molecules to products
2 advantages of the hydrogenation of fats
- Prolong shelf life
- Alters texture of food
Trans fatty acids
- Molecules remain unsaturated after processing
- Milk and butter
Sources of trans fats
- Margarine
- Cakes
- Meat
- Dairy products
- Penut butter
Essential fatty acids
- Must be supplied by the diet
- Main structural parts of cell membranes
An example of an omega-6 fatty acid
Linoleic acid
An example of an omega-3 fatty acid
α-Linolenic acid
Linoleic acid
- Omega-6
- Cannot be made by the body
- Vegetable oils and meats
α-Linolenic acid
- Omega-3 fatty acid
- 18 carbon acid
- Cannot be made by the body
- Normal brain development
- Prevent diseases
Deficiencies of essential fatty acids (EFA) can lead to
- Poor growth
- Cognitive development
- Reproductive failure
- Skin lesions
- Kidney and liver failure
What are the 4 types of lipoproteins
- Chylomicrons
- VLDL
- LDL
- HDL
Chylomicrons
Transport mainly dietary triglyceride to cells
Very low density lipoprotein
Transports mainly triglycerides made from the liver to the cells
LDL
Transports cholesterol to cells
HDL
Transports cholesterol from cells back to the liver
N-3 (Omega-3)
- RI = 0.2%
- Oily fish, yoghurts, spreads
Saturated fat
- Risk factor for CVD
- Increases LDL
Trans fats
- Processed foods
- Margarines, cakes, milk, red meat
- DRV = less than 2%
- Increase risk of CHD
