Lipid Chem And Digestion

Question 1

Lipids are soluble/insoluble in

(1) H2O
(2) nonpolar solvents e.g. ether & chloroform

Answer 1

1. Insoluble

2. Soluble

Question 2

Where are lipids located in the body?

Answer 2

BAP

Biological membrane
-PPLs

Adipose tissue
-TAG

Plasma
-FA

Question 3

Lipid Classification

Answer 3

A. Simple Lipids

1. Fats/Triglycerides/TAGs
2. Waxes

B. Complex Lipids

1. PPLs
2. Glycolipids

C. Derived lipids

Question 4

Most metabolically active lipid? This lipid is produced from?

Answer 4

Fatty Acids

-Produced from Acetyl-CoA and NADPH through FA synthases

Question 5

Mechanism of:

1. Desaturase
2. FA Elongase

Answer 5

-

Question 6

PPL which is a major component of pulmonary surfactant?

• Attachments
• Charge at physiologic pH
• location in the membrane

Answer 6

Phosphatidylcholine

Attachments

• C1 attached to saturated fatty acid (palmitic acid or stearic acid)
• C2 attached to polyunsaturated fatty acid (linolenic acid, linoleic acid, or oleic acid)
• C3 attached to phosphate with + alcohol
• Zwitterion
• Most abundant PPL on the outer leaflet

Question 7

PPL found at nervous tissues

• Structure
• Charge
• Location

Answer 7

Phosphatidylethanolamine

Attachment:

• C1 attached to saturated fatty acid (either palmitic acid or stearic acid)
• C2 attached to polyunsaturated fatty acid (arachidonic acid, linoleic acid, or docosahexaenoic acid)
• Arachidonic acid can be a precursor to eicosanoids
• Zero net charge
• 2nd most abundant PPL in the inner leaflet of cell membrane

Question 8

PPL important in cell signaling and blood coagulation

• Attachment
• Charge
• Location? Does it go to the other side

Answer 8

Phosphatidylserine

-C1 attached to saturated fatty acid
-C2 attached to long chain polyunsaturated fatty acid (may be
arachidonic acid)
-C3 attached to phosphate + alcohol

-Net of -1 charge
Where Ca2+ binds to initiate clotting

-Present in the inner leaflet. However, upon aging, accumulates to outer leaflet triggering apoptosis. Flippases maintain phosphatidylserine supposedly on the inner leaflet.

Question 9

PPL important in cell signaling and membrane trafficking; most acidic glycerophospholipid

• Attachments
• Charge

Answer 9

Phosphatidylinositol

Attachments:

• C1 attached to saturated fatty acid (stearic acid)
• C2 attached to polyunsaturated fatty acid (arachidonic acid)
• C3 attached to inositol

-Charge: -4

Question 10

Precursor of cardiolipin

• Attachments
• Also a component of?
• Charge
• Location

Answer 10

Phosphatidylglycerol

Attachment:

• Two phosphatidic acids attached to C1 & C3
• C2 attached to hydroxyl group
• Charge: -1
• Also a component of pulmonary surfactant

Question 11

What is a sphingosine? When N-acetylated it becomes?

Answer 11

Product of oxidative decarboxylation and condensation of palmitate and serine

Ceramide - N-acetylated sphingosine
-backbone of sphingomyelin and glycolipid

Question 12

Found in the myelin sheath of nerves

Answer 12

Sphingomyelin

Question 13

Glycolipids

1. Neutral Glycolipid
2. Globoside
3. Sulfatide
4. Ganglioside
5. Cerebroside

Answer 13

1. Neutral Glycolipid
   - contains 1 amino sugar
2. Globoside
   - contains ceramide + 2+ sugars
3. Sulfatide
   - ceramide + sugar + sulfate
4. Ganglioside
   - globoside + N-acetylneuraminic
5. Cerebroside
   -Galactocerebroside
   =ceramide + galactose attached at C1
   -Glucosyl cerebroside
   = ceramide + glucose attached at C1

Question 14

Cholesterol

Answer 14

-