TG, PL, SPL

Question 1

TG and PL are synthesized _

Answer 1

cytosolic side of ER and lesser extent OMM

Question 2

Common intermediate of TG and PL synthesis

Answer 2

Phosphatidic Acid

Question 3

Major stored form of E in adipose

Answer 3

TG

Question 4

Formation of TG

Answer 4

Glyercol 3P > PA > diacyl glycerol > TG

Question 5

CM transports TG to _ and dietary cholesterol to _

Answer 5

Various tissues(muscle adipocytes)
Liver only

Question 6

Apoproteins on CM

Answer 6

• ApoC…activates lipoprotein lipase > hydrolyze TG > release F.A. for storage/E in adipocytes or muscle
• ApoB48…marker of CM
• ApoE…recognition protein
• ApoB48, ApoE responsible for cholesterol transport to liver by remnant CM via endocytosis

Question 7

LDL has which apoprotein?
Deficiency can cause?

Answer 7

• Apo100
• Hypercholesterolemia

Question 8

Formation of PL(de novo)

Answer 8

PA > CDP-DAG by cytidyl transferase…+ serine > PS and CMP
or CDP-DAG + inositol > PI(CNS)

Question 9

Dipalmitoyl PC deficiency in lung

Answer 9

Respiratory distress syndrome

Question 10

_ cause skin cancer by activating PKC
They are structural analogues of _

Answer 10

• Phorbol esters
• DAG

Question 11

PL salvage pathway

Answer 11

Methionine intake limited > choline re-salvaged > choline phosphate > CDP-choline via cytidyl transferase…+ DAG > PC

Question 12

Defect in salvage pathway leads to(kinase or transferase)

Answer 12

Fatty liver
(DAG accumulates > TG)

Question 13

PL drug carrier _

Answer 13

Liposome

Question 14

Hydrolyze…
PLA1:
PLA2:
PLC:
PLD:

Answer 14

• first ester bond
• fatty acyl ester bond at position 2
• releases head groups of PL + DAG
• releases head groups + PA

Question 15

T/F: Sphingolipids are involved in ABO blood types

Answer 15

True

Question 16

Synthesis of SPL occurs in _

Answer 16

ER membrane

Question 17

RDS in SPL synthesis

Answer 17

Serine palmitoyl transferase(B6)
Palmitic acid + serine

Question 18

SPL synthesis steps

Answer 18

after RDS rxn…keto > sphinganine > dihydroceramide > ceramide via cermide synthase

Question 19

PAPS?

Answer 19

• Phosphoadenosyl phosphosulfate
• Sulfates neutral glycolipids > sulfatids

Question 20

SPL catabolism(lysosomal enzymes)

Answer 20

Release CBHY > Ceramide > sphingosine + F.A. via ceramidase(amide)

Question 21

Sphingolipidoses characterized by (4)

Answer 21

• abnormal amount of SPL > organomegaly
• Defect in catabolic enzymes only
• Affect all tissues the same
• Mental retardation

Question 22

Gaucher’s:
Krabbe’s:
Nielmann-pick:
Tay Sacch’s:
Farber’s:

Answer 22

• Glucocerebrosidase deficiency
• Galactocerebrosidase deficiency
• Sphingomyelinase deficiency
• Hexoaminidase deficiency
• Ceramidase deficiency

Question 23

Opposed to sphingolipidoses, demyelination/degradation causes _

Answer 23

Multiple sclerosis