14_Biochem Block 3.1 Lipids

Front 1

Also, what is the backbone?

Back 1

1. Phosphatidic acid
2. Ester
3. On a glycerol backbone

Front 2

Where does synthesis of phosphatidic acid take place?

Back 2

It occurs in the endoplasmic reticulum and outer mitochondrial membrane.

Front 3

What is phosphatidic acid and what are its basic components?

Back 3

1. Glycerol Backbone
2. Saturated fatty acid on C1
3. Unsaturated FA on C2
4. Phosphate group on C3

Front 4

Where does synthesis of phosphatidic acid take place?

Back 4

It occurs in the endoplasmic reticulum and outer mitochondrial membrane.

Front 5

What is phosphatidic acid and what are its basic components?

Back 5

1. Glycerol Backbone
2. Saturated fatty acid on C1
3. Unsaturated FA on C2
4. Phosphate group on C3

Front 6

Draw the simplest phosphatidic acid.

Back 6

NOTE: There's not an extra H on C2 as pictured.

Front 7

Synthesis of PHOSPHATIDATES can be achieved in two ways - both require a charged intermediated. What are these two intermediates and what creates them? (p220)

Back 7

(Note: I had a problem making this card - the image represents the first method only)
1. A charged Phosphatidic acid made with CTP.
2. A charged alcohol also made from CTP

Front 8

Second to nucleic acid synthesis what is the most important role of CTP? (Make sure you know the two rxns using CTP on p220)

Back 8

Phospholipid biosynthesis.

Front 9

Ether phospholipids are characterized by an ether linkage at the:
What are the three ingredients of Ether Phospholipids? (p222)
How are they typically used in the cell?

Back 9

1. C1 Carbon
2. Dihydroxyacetone, long-chain fatty acids, and long-chain fatty alcohols.
3. Second messenger signaling - e.g. PAF

Front 10

Review the Ether Phospholipid pathway on p222

Back 10

Review the Ether Phospholipid pathway on p222

Front 11

What type of phospholipid is Platelet Activating Factor? What does PAF induce? (p222) How is the structure unusual compared to other phospholipids? What does this enable it to do?

Back 11

Ether phospholipid. Induces immune responses. It includes an acetyl group at C2 instead of a FA. This increases its solubility and allows it to function in an aqueous environment.

Front 12

What are Plasmalogens? What enzyme is key to their synthesis? Where is this enzyme located? (p223)

Back 12

Ether phospholipids that contain an unsaturated ether at C1. Desaturase catalyzing enzyme oxidizes the saturated FA at C1 to an unsaturated FA at C1. The oxidase enzyme is located in the ER.

Front 13

What are Phospholipases? What are they're two major activities?

Back 13

The specifically cleave phospholipids. They are involved in 1) phospholipid remodeling and 2) intracellular signaling.

Front 14

Phospholipase A1 and Phospholipase A2 remove FAs from which Carbons on the glycerol backbone? What does this permit? What role does Phospholipase C and Phospholipase D have?

Back 14

C1 and C2 respectively. Permits re-esterification rxns with other FA CoAs (i.e. remodeling).

Phospholipase C cleaves C3 phosphodiester to Diacylglycerol and Phospholipase D cleaves C3 to produce Phosphatidic acid (signaling).

Front 15

Draw a diagram showing where each of the four phospholipases cleave. Name the products of C and D.

Back 15

C makes diacylglycerol
D makes phosphatidic acid.

Front 16

Based on your knowledge of phospholipases, what would cleavage of PIP2 (phosphatidylinositol 4,5-bisphosphate) by phospholipase C produce? (p224)

Back 16

Diacylglycerol (DAG) and Inositol 1,4,5-triphosphate (IP3).

Front 17

Describe how cleavage of PIP2 by phospholipase C (PLC) causes cellular response. (P225).

Back 17

Hormone binds and activates PLC. PLC cleaves PIP2 to DAG and IP3. DAG remains bound to membrane and IP3 migrates to ER where it stimulates Ca2+ release. Ca2+ and DAG activate PKC and initiate cellular responses.

Front 18

How are proteins typically anchored to the PM? How are they typically arranged? How can they have a signaling function? (p225)

Back 18

Glycosyl Phosphatidylinositol (GPI) is an anchor that allows some extracellular proteins to be anchored to the plasma membrane. They are typically arranged in clusters that can easily be released for signaling purposes by Phospholipase C.

Front 19

What are eicosanoids? What are they synthesized from? Since eicosanoids are FAs, what do they have to do with membrane Phospholipids? (p226)

Back 19

They are short-lived paracrine hormones that act locally on various tissues/systems (think pain, think aspirin, think COX inhibitor). Synthesized from arachidonic acid. Since arachidonic acid is typically bound to C2 in membrane-bound phosphopholipids, it is readily available for synthesis.

Front 20

What are the functions of:
1. Prostacyclin (PGI2)
2. Prostaglandin (E2)
3. Thromboxane A2
(p227)

Back 20

1. Vasorelaxation and platelet declumping
2. Fever, pain, uterine contraction,
3. Vasoconstriction and platelet activation

Front 21

Of prostacyclin, prostaglandin, and thromboxane, which are 5-member rings and which are 6 member?
(p277 - might want to review this page - lots of stuff)

Back 21

Prostaglandins and prostacyclin are 5-member rings. Thromboxane is a 6-member ring.

Front 22

For the prostaglandins, where are their functional groups located?

Back 22

On the cyclopentane ring.

Front 23

What is a defining feature of all leukotrienes? How many O2 are added to arachidonic acid to make leukotriene?

Back 23

Four double bonds. 1 Oxygen molecule

Front 24

What is the difference between cycloxygenase and lipoxygenase?

Back 24

Cycloxygenase catalyzes addition of two oxygen molecules. Lipoxygenase catalyzes addition of one oxygen to arachidonic acid.

Front 25

What are lipoxins characterized by?
What are leukotrienes characterized by?

Back 25

Lipoxins = hydroxyl groups at C5 and C6
Leukotrienes = 4 double bonds.

Front 26

Leukotrienes and Lipoxins have a yin/yang relationship. Describe that.

Back 26

Leukotrienes are pro-inflammatory substances and Lipoxins are anti-inflammatory.

Front 27

Review p230 for how Leukotrienes and HETE's are targeted pharmacologically:
1. 5-LO's FLAP protein is targeted
2.

Back 27

Review p230 for how Leukotrienes and HETE's are targeted pharmacologically.

Front 28

Draw/compare a phospholipid to a sphingolipid.
*the drawing is wrong - should have an amine at C2

Back 28

Front 29

For sphingolipids, what is the backbone (i.e. the equivalent to glycerol in phospholipids)? Where/how do they differ?

Back 29

Ceremide. They differ by their polar head group on C3.

Front 30

For Sphingomyelins, Glycosphingolipids, and Gangliosides, describe 1) the polar group at C3 and 2) where they are most abundant. (p 231)

Back 30

Sphingomyelins: 1) Phosphocholine and Phosphoethanolamine. 2) Mostly found on Myelin
Glycosphingolipids: 1) Cerebrosides (one sugar group) or Globosides (more than one sugar group) 2) Found at outer surface of the plasma membrane
Gangliosides 1) Oligosaccharides with one or more N-acetylneuraminic acid 2) Found in gray matter.

Front 31

What two compounds are used to synthesize sphingosine? What is the source of C1, C2,the amino group, and the remaining C atoms?

Back 31

Palmitoyl CoA and Serine. Serine provides C1, C2 and the amino group while Palmitic acid provides the remaining carbons.

Front 32

In Sphingosine synthesis, what role does NADPH and FAD play? (p232)

Back 32

NADPH reduces the carbonyl to a hydroxyl group and FAD introduces a double bond.

Front 33

What molecule is this? Based on what?

Back 33

Sphingosine. Based on the Hydroxyl, Amino, Hydroxyl group on carbons 1, 2, and 3.

Front 34

Once sphingosine is made, what is the next step? (p232)

Back 34

Addition of a long-chain fatty acyl-CoA to produce Ceramide.

Front 35

Once ceramide is made, what can be added and where are these groups added? (p232)

Back 35

To the terminal hydroxyl group on Ceramide, Phosphatidyl Choline can be added or UDP-Glucose

Front 36

If Phosphatidyl Choline is added to ceramide, what does it make? What if UDP-Glucose is added?

Back 36

Sphingomyelin and Cerebroside respectively.

Front 37

Describe the general synthesis of gangliosides. What enzyme adds these sugars?

Back 37

It begins with cerebrosides and proceeds through globosides until a sialic acid residue is attached. Glycosyltransferases adds sugars to the structure.

Front 38

What terminates the addition of sugars in ganglioside synthesis?

Back 38

Sialic residue.

Front 39

When sphinglolipids are degraded in lysoymes, what is produced? What is the condition called when sphingolipids cannot be broken down in the body?

Back 39

Sphingosine and fatty acids. Sphingolipidoses.

Front 40

What causes Tay-Sach's disease?

Back 40

It's a disorder of ganglioside degradation caused by a deficiency in Beta-hexosaminidase. Neurons become swollen with lipid filled lysozymes (i.e. everything upstream of defect is accumulating).

Front 41

What is Niemann-Pick diease?

Back 41

A deficiency in sphingomyelinase that degrades sphingomyelin into ceramide and phosphocholine. As a consequence, everything upstream accumulates and causes problems.

Front 42

What are polyisoprenoids composed of? What are some examples of important ones?

Back 42

Derived from 5-carbon isoprene units rather than fatty acids. Important ones include cholesterol, steroid hormones, bile acids.

Front 43

Steroids are characterized by a ?-ring structure that is synthesized from what?

Back 43

4-ring; squalene

Front 44

Name these compounds that are important moieties added to phosphatidates.

Back 44

1. Water
2. Choline
3. Ethanolamine
4. Serine
5. Glycerol
6. Phosphatidyl-glycerol
7. myo-Inositol

Front 45

What molecule is this? What are two unique things about it at C1 and C2?

Back 45

Platelet Activating Factor.
1. Has an ether group at C1
2. Has acetyl moiety at C2 rather than long chain FA. This makes it very water soluble.
**note - it mediates anaphylactic shock

Front 46

Why might it be useful to take a baby aspirin every day? p227

Back 46

Bc aspirin inhibits thromboxane synthesis longer than prostacyclin synthesis. Since prostacyclin is involved in vasorelaxation and platelet declumping, then less likely to have a blood clot. But then, more likely to bleed out.