Lecture 13

Question 1

What is a lipid?

Answer 1

• made of fatty acids
• insoluble in water
• organic

Question 2

What are the types of lipids?

Answer 2

• triglycerides (most common)
• fatty acids
• phospholipids
• sterols
• fat soluble vitamins

Question 3

What makes up 90% of dietary lipid?

Answer 3

triglycerides

Question 4

What are the functions of triglycerides?

Answer 4

• energy storage
• fatty acid storage
• structural component of lipoproteins

Question 5

What is the structure of triglycerides?

Answer 5

1 glycerol attached to 3 fatty acid chains

Question 6

What is a fatty acid?

Answer 6

chain of carbon molecules with a methyl group at one end and a carboxyl group at the end of the chain

Question 7

What are the important differences for different fatty acids?

Answer 7

• length of chain
• double bonds (affects melting point)
• position of 1st double bond from methyl end

Question 8

What is a saturated fatty acid?

Answer 8

• saturated with hydrogen
• high melting point

Question 9

What is a monounsaturated fatty acid?

Answer 9

1 double bond

Question 10

What is a polyunsaturated fatty acid?

Answer 10

• low melting point
• multiple double bonds

Question 11

What fatty acids can the body not make?

Answer 11

ones with double bonds within the first 6 carbons from the methyl group

Question 12

What are the essential fatty acids?

Answer 12

• linoleic acid
• linolenic acid

Question 13

What % of total energy should be from essential fatty acids?

Answer 13

1-3%

Question 14

What are the symptoms of essential fatty acid deficiency?

Answer 14

• growth retardation
• reproductive failure
• skin lesions
• kidney and liver disorders
• neurological and visual problems

Question 15

When elongating essential fatty acids, what stays the same?

Answer 15

location of the first double bond

Question 16

Why are Long chain polyunsaturated fatty acids needed?

Answer 16

• n-6 for the last trimester of pregnancy and first 2 years of life
• n-3 for the brain, makes up most of its mass

Question 17

What foods have mostly saturated fat?

Answer 17

animal and tropical oils

Question 18

What oils are rich in monounsaturated fat?

Answer 18

some vegetable oils e.g olive, canola, peanut

Question 19

What oils are rich in polyunsaturated fat?

Answer 19

many vegetable oils

Question 20

What are sphingolipids?

Answer 20

• made from phospholipids
• primarily found in brain and nervous tissue

Question 21

What are prostglandins?

Answer 21

• made from phospholipids
• important for signalling

Question 22

What are sterols?

Answer 22

• multiple ring structures
• found in plant and animal foods
• cholesterol only found in animal foods
• plant sterols lower cholesterol