Lipid Flashcards
Energy content of fat
1 gram = 37 kJ
What is glycolysis?
The process of glucose catabolism into pyruvate for energy.
Types of monounsaturated fats:
Fructose, galactose and glucose
Contain one double bond.
Types of polyunsaturated fats
All essential fatty acids.
Omega 3 & Omega 6.
Contain more than one double bond.
Liquid at room temperature.
What is the hydrogenation process?
Changes oil structure from cis to trans, impacting lipid properties.
What are essential fatty acids (EFAs)?
LA & ALA
Not produced endogenously, must be obtained from the diet.
Key functions of essential fatty acids
Found in all cell membranes and required for eicosanoid production.
Arachidonic Acid (Omega-6) characteristics
Pro-inflammatory except for gamma-linolenic acid (GLA).
EPA & DHA (Omega-3) characteristics
Anti-inflammatory long-chain fatty acids.
Increased demand for Omega-3 reasons
Chronic digestive diseases, chronic physiological stress, unbalanced diets.
Precautions for high-dose Omega-3 supplementation
Risk of abnormal bleeding (especially with anti-hypertension drugs).
Supplement with vitamin E to protect against oxidative damage.
Recommended Omega-6 to Omega-3 ratio
Between 2:1 and 5:1.
Functions of phospholipids
Major component of cell membranes, component of bile and lipoproteins.
Functions of cholesterol
Structural component of cell membranes, precursor for bile acids and vitamin D.
Plant sterols function
Effective for managing hypercholesterolaemia (high cholesterol).
WHO recommendation for saturated fat intake
Saturated fat should not exceed 10% of total energy intake.
What are lipids?
A family of compounds including triglycerides, phospholipids, and sterols; insoluble in water.
What are triglycerides?
Main dietary fat and primary lipid storage form in the body.
Structure: Glycerol backbone with three fatty acid tails.
What are phospholipids?
Similar to triglycerides but contain a phosphate group and choline in place of one fatty acid.
What are sterols?
Compounds with a four-ring carbon structure.
Example: Cholesterol.
General functions of lipids
Cell membranes and organelle membranes, energy storage, insulation, protection of organs.
Structure of fatty acids (FA)
Carboxylate (COOH) end attaches to glycerol; methyl (CH3) end is the omega group.
Saturation of fatty acids
Saturated FAs: No double bonds; Monounsaturated FAs: One double bond; Polyunsaturated FAs: Multiple double bonds.
What are trans fats?
Artificial trans fats are created by hydrogenation; natural trans fats are found in dairy and ruminant animals.
Key sources of Omega-6 (LA)
Vegetable oils, meat, eggs, poultry.
Key sources of Omega-3 (EPA/DHA)
Oily fish like salmon and sardines.
Key sources of Omega-3
a-Linolenic Acid - ALA
Linseeds, walnuts.
What is the AI for Omega-6?
Linoleic acid - LA
Female: 8 g/day
Men: 13 g/day
What is the AI for (Omega-3)?
a-linolenic acid - ALA
Female: 0.8 g/day
Male: 1.3 g/day
What is the AI for Total LC n-3
(DHA+EPA+DPA) - Long Chain?
Female: 90 mg/day
Male: 160 mg/day
What is the recommended total energy intake for Fats?
20-35%
Saturated <10%
Trans <1%
