Fats

Question 0

Why do we need dietary fat?

Answer 0

Important source of food energy
Provides and enables the absorption of fat soluble vitamins (A, D, E, K)
Provides essential fatty acids (n-6, n-3)
Makes food palatable as it dissolves flavours and has a characteristic mouth-feel

Question 1

What is the Atwater factor of fat?

Answer 1

9kcal/g

Question 2

What are some classifications of lipids?

Answer 2

Triglycerides
Fatty acids
Phospholipids
Glycolipids
Sterols

Question 3

What are the two systems of naming and how do they name fatty acids?

Answer 3

Delta- double bonds counted from carboxyl end

Omega- double bonds counted from methyl end

Question 4

What are the essential fatty acids?

Answer 4

n-6 linoleic acid, n-3 linolenic acid (cannot be synthesised)

Question 5

What are the dietary sources on linolenic acid?

Answer 5

Plant oils (soybean, rapeseed, linseed)
Eicosapentaenoic acid (fish oil)
Docosahexaenoic acid (fish oil, organ meats)

Question 6

What are the dietary sources of linoleic acid?

Answer 6

Vegetable oils- corn, soybean, sunflower
Gamma-linolenic acid- primrose, black currant seed oil
Arachidonic acid- meat, offal, eggs

Question 7

What are some health benefits of omega-3 fatty acids?

Answer 7

Reduces- ventricular arrhythmia, atherosclerotic plaque, blood clots, stroke
Antithrombogenic
Anti inflammatory

Question 8

How is cholesterol stored?

Answer 8

In liver in esterified form

Question 9

What is cholesterol a precursor for?

Answer 9

Vitamin D
Steroid hormones
Bile acids

Question 10

Why are lipoproteins needed to transport lipids?

Answer 10

Because blood is a liquid medium and lipids are insoluble thus cannot be transported in their free form

Question 11

How do lipids leave the intestinal cells?

Answer 11

Too big once in chylomicron form to enter bloodstream through capillary so must enter systemic blood flow via thoracic duct (lymphatic system)