Lipids 1

Question 1

Name 4 lipid classes

Answer 1

• Phospholipids
• Fatty acids
• Steroids
• Glycolipids

Question 2

What causes unsaturation of fatty acids?

Answer 2

C=C double bonds cause a kink in the chain, therefore more liquid

Question 3

At how many carbons long can humans no longer produce double bonds?

Answer 3

Can’t produce bonds beyond carbon 9

Question 4

Name two essential fatty acids

Answer 4

Linoleic and linolenic acid

Question 5

What does linolenic acid produce?

Answer 5

Omega 3 FA’s, essential in lowering LDL.

Question 6

What are bile salts?

Answer 6

Emulsifiers that allow enzymes to break down FA’s

Question 7

What do lipids exist as in the blood?

Answer 7

Lipoproteins

Question 8

Where does chylomicron transport FA’s to and from?

Answer 8

intestine to tissue (adipose)

Question 9

VLDL

Answer 9

liver to tissue

Question 10

LDL

Answer 10

cholesterol from tissue to cavities

Question 11

HDL

Answer 11

tissue to liver for elimination

Question 12

How is TAG digested?

Answer 12

• degraded to monacylglycerol and 2 FA’s by pancreatic lipase
• absorbed through mucous cells in the small intestine

Question 13

What is steatorrhea and who is most susceptible?

Answer 13

excess fat in faeces causing foul smelling, floating faeces. CF sufferers

Question 14

Removal of what organ reduces FA digestion?

Answer 14

Gall bladder - it produces bile

Question 15

How are TAG stores used in response to hunger?

Answer 15

• Epinephrine released
• HSL phosphorylated
• HSL then releases FA’s from TAG

Question 16

How is HSL inhibited?

Answer 16

High blood [glucose]

Question 17

How are dietary lipids transported following digestion?

Answer 17

• Insoluble lipids packaged into chylomicron
• Transported to adipose tissue and resynthesised into TAG for storage
  OR
• Transported in and released into the lymph.

Question 18

Chylomicron

Answer 18

• made of apoB-48 to allow transport of insoluble lipids

- contain lipoprotein lipase that degrades TAG into glycerol and FA.

Question 19

How are phospholipids digested?

Answer 19

Broken down into lysophospholipid and FA.

Question 20

What can glycerol be used for?

Answer 20

In the liver it can produce glycerol 3 phosphate which can be used on glycolysis.