Nutritional Properties of Lipids

Question 1

What is fats primary role?

Answer 1

As a source of energy

Question 2

What are the functions of lipids?

Answer 2

Source of energy
Storage (triglycerides store forms of fat)
Bilayers
Sterols

Question 3

What affect do saturated fats have on fluidity of membranes?

Answer 3

Reduce fluidity

Question 4

What affect do unsaturated fats have on fluidity of membranes?

Answer 4

Increases fluidity

Question 5

What affect do long chain fatty acids have on fluidity of membranes?

Answer 5

Reduce fluidity

Question 6

What affect do short chain fatty acids have on fluidity of membranes?

Answer 6

Increase fluidity

Question 7

What affect does cholesterol have on membranes?

Answer 7

Regulates fluidity by preventing crystallisation but blocking large motions of acyl chain

Question 8

What are the functions of cholesterol?

Answer 8

Synthesis of bile salts

Synthesis of hormones

Question 9

Where does the metabolism of fatty acids occur?

Answer 9

In the mitochondria

Question 10

What must fatty acids be bound to in order to enter the mitochondria?

Answer 10

Carnitine

Question 11

How does metabolism of fatty acids generate energy?

Answer 11

Via beta oxidation

Question 12

Why is it essential that omega 3 and 6 fatty acids are obtained in the diet?

Answer 12

Because the body cannot synthesis these fatty acids due to the lack of the enzyme desaturase

Question 13

What is a source of omega 3 fatty acids?

Answer 13

Fish oils

Question 14

What is a source of omega 6 fatty acids?

Answer 14

Vegetable oils

Question 15

What are omega 3 and 6 fatty acids involved in?

Answer 15

Regulating membrane structure

Question 16

What are omega 3 and omega 6 fatty acids a precursor for?

Answer 16

Eicosanoids = signalling molecules involved in immunity and inflammation

Question 17

Name two foods high in saturates.

Answer 17

Meat products

Coconut

Question 18

Name three foods high in monosaturates.

Answer 18

Olives
Vegetable oils
Nuts

Question 19

Name three foods high in polysaturates.

Answer 19

Cereals
Fish
Plant oils

Question 20

Name three foods high in trans unsaturated fatty acids.

Answer 20

Meat and dairy (low)
Processed foods (high)
Spreading fats (high)

Question 21

What foods is fat mainly obtained by?

Answer 21

Meat products and cereal products

Question 22

What form is fat mainly obtained in?

Answer 22

Triglycerides

The rest is in phospholipids and cholesterol which have fat soluble vitamins associated with the,

Question 23

What are the health effects of excessive fat intake?

Answer 23

Hyperlipidemia = high lipid blood levels 
Cardiovascular disease 
Obesity 
diabetes mellitus 
Cancer = breast, colon and prostate

Question 24

Why are there no DRVs for fats?

Answer 24

Because they are not essential nutrients (other than omega 3 and omega 6 fatty acids)

Question 25

What are used instead of DRVs for fat?

Answer 25

EARs

Question 26

What is the recommendation for percentage energy intake in the form of fat?

Answer 26

33-34%