Lipids

Question 1

Lipids are synthesized from _______.

Answer 1

Acetyl CoA

Question 2

How are lipids used for structural support?

Answer 2

Mechanical and electrical insulation; serve as anchors that tethers proteins to membranes

Question 3

How are lipids used for signaling events?

Answer 3

Cofactors; signaling molecules during development; immune response, vision, etc.

Question 4

How do lipids provide mechanical protection and thermal insulation?

Answer 4

Adipose tissue

Question 5

What are the two broad classes of lipids?

Answer 5

fatty acid derivatives and isprenoids

Question 6

What is a lipid?

Answer 6

water insoluble bio molecule that is highly soluble in organic solvents: hydrophobic properties are due to fatty acids

Question 7

Describe fatty acid derivatives

Answer 7

Monocarboxylic acid with a long hydrocarbon chain

Question 8

What are examples of fatty acid derivatives?

Answer 8

glycerides, membrane lipids, and eicosanoids

Question 9

What does the inefficient expression of lipase lead to?

Answer 9

gastrointestinal problems

Question 10

Where are fatty acids oxidized?

Answer 10

mitochondria to generate ATP

Question 11

What are two examples of saturated fatty acid derivatives?

Answer 11

palmitic acid and Stearic acid

Question 12

What are 3 examples of unsaturated fatty acid derivatives?

Answer 12

Oleic acid
Linoleic acid
and arachidonic acid

Question 13

What can supplement for lipase when not available?

Answer 13

Bile salts

Question 14

isoprenoids contain multiple units of a five carbon molecule, called isoprene.
What are two examples of isoprenoids?

Answer 14

Cholesterol and bile salts

Question 15

describe ω-3 and ω-6 fatty acids

Answer 15

Omega-3 fatty acids are essential fatty acids whose final double bonds are located 3 carbons from the end of their hydrocarbon tails. Linolenic acid is common

Omega-6 have last double bond 6 carbons from the end of hydrocarbon tails; linoleic acid and arachidonic acid

Question 16

What are components of lung surfactant? What is the function?

Answer 16

Phosphatidylcholine (lecithin), sphingomyelin, and phosphatidylglycerol

serves as a lubricant that lowers the surface tension of alveoli, making it easier for the lung to expand

Question 17

What causes respiratory distress syndrome

Answer 17

Immature lungs of preterm infant often fail to produce surfactant and leads to RDS, impairing gas exchange and increasing risk of partial lung collapse.

*Test measures lecithin to sphingomyelin ratio in amniotic fluid allows for the maturity of a fetus’s lungs to be determined. Ratio less than 2:1 indicates deficiency and possible RDS. Ratio greater means mature lungs

Question 18

What causes gallstones?

Answer 18

Gallbladder stores bile, a lipid-emulsifying liquid. Cholesterol normally found in bile needs bile salts to stay in solution. Too much cholesterol and too little bile salts = cholesterol hardens into pebble solids.

Question 19

What can the continued disturbance of bile salt metabolism lead to?

Answer 19

malabsorption syndromes such as steatorrhea and extreme cases, deficiency in fat-soluble vitamins.

*Oral chenodeoxycholic acid used to replace bile acid pool and can help dissolve stones