Dietary Fats And Blood Lipids Lab Flashcards
What is the energy content per unit weight of fats?
Approx 9 kcal/g
What is the energy content per unit weight of proteins and carbohydrates?
Approx 4 kcal/g
In terms of the general population, what proportion of our energy should come from fats?
About a third:
- 70g per day for women
- 90g per day for men
List some of the molecules which are considered ‘fats’.
- sterols e.g. cholesterol
- phospholipids
- triglycerides
What is a fatty acid?
A carboxylic acid (COOH) with a long chain of hydrocarbons.
How many fatty acids does a triglyceride contain?
3
How many fatty acids does a phospholipid contain?
2
How many fatty acids does cholesterol contain?
1
How much saturated fat does the government recommend men and women consume each day?
Women < 20g
Men < 30g
What is a saturated fat?
A fat with no double bonds between carbon atoms.
What is an unsaturated fat?
A fat with 1 or more double bonds between carbon atoms (mono- or poly-).
What are the main types of polyunsaturated fats?
Omega-3 and omega-6
What are the 2 distinct structural configurations of unsaturated fatty acids?
Cis and trans
Describe cis-unsaturated fatty acids.
- hydrogen atoms attached to the carbon double bond on the same side
- have a bent configuration
Describe trans-fatty acids.
- hydrogen atoms attached to carbon double bonds on different sides
- generally linear in structure
- do not occur commonly in nature, usually produced by industrial hydrogenation
List some examples of foods high in saturated fat.
- pastry
- coconut oil
- hard cheese
- soured cream
List some examples of foods high in mono-unsaturated fat.
- avocado
- olives
- rapeseed oil
List some examples of foods with poly-unsaturated fat.
- salmon
- rapeseed oil
- walnuts
Why is fat essential for the body?
- provides energy, essential fatty acids and fat soluble vitamins (A, D, E, K)
When are fats referred to as lipids?
Once they are digested and absorbed in the bloodstream
Why are lipids transported in lipo-proteins?
Because they are insoluble in water and blood.
Describe the basic structure of a lipoprotein.
- complex spherical structure
- hydrophobic core
- hydrophilic coating
What is found in the hydrophobic core of lipoproteins?
Triglycerides and cholesterol esters
What is contained in the hydrophilic surface of lipoproteins?
Phospholipids, free cholesterol and apolipoproteins.