01 TAG & Phospholipid

Question 1

Where does TAG synthesis happen mostly?

Answer 1

Liver and adipose tissue

Question 2

What are the substrates dor TAG ?

Answer 2

Glycerol and 3 FA(fatty acid)

Question 3

What is the precursor for TAG and Glycerophospholipids ?

Answer 3

Phosphatidic acid

Question 4

What is the common intermidiate compound for the synthesis of triacylglycerol?

Answer 4

Glycerol 3-p Which deffer in liver and adipose tissue

Question 5

Where is glycerol 3-p produced?

Answer 5

In liver, by phosphorilation of glycerol by using enzyme glycerol kinase.
Or by reduction of dihydroxyacetone phosphate(DHAP) which is derived from glycolysi.
In adipose tissue only by reduction of DHAP

Question 6

Where is glycerol kinase enzyme present?

Answer 6

In the liver. And it is absent in adipose tissue, that is why adipose tissue produces glycerol 3-p by only DHAP and not by phosphorylation of glycerol.

Question 7

What is the way glycerol 3-p is produced in adipose tissue?

Answer 7

Only by DHAP which is an intermediate of Glycolysis.

So glycerol 3-p is produced by reduction of DHAP.

Question 8

An important connection between carbs and lipid metabolism?

Answer 8

DHAP (dihydroxyacetone phosphate)

Question 9

What happens when you eat alot of carbs?

Answer 9

Carbs are converted into adipose tissue ( Triglycerols)

Question 10

What is the common intermediate for triglycerol synthesis in both liver and adipose tissue?

Answer 10

Glycerol 3-phosphate

Question 11

Glucose which comes from carbs metabolism is converted into DHAP then into Glycerol 3-p. Where does this happen?

Answer 11

Liver and adipose tissue

Question 12

Glycerol is converted to glycerol 3-p. Where this happens?

Answer 12

In liver only.

Question 13

TAG produced from ……………… is packaged with cholesterol, phospholipids and protiens to form …………… .

Answer 13

Liver

VLDL

Question 14

Triglecerol (TAG) formed in liver goes to …………

Answer 14

Blood as VLDL

Question 15

Triacylglycerol (TAG) formed in adipose tissue is ……..

Answer 15

Stored in adipose

Question 16

How many fatty acids (FA) are needed to convert glycerol 3-p to TAG ?

Answer 16

3 FA

2 of them used in ( glycerol 3-p to phsphatidic acid )

1 is used ( diacylglycerol to triacylglycerol )

Question 17

In TAG SYNTHESIS , glycerol 3-p is converted to ?

Answer 17

Glycerol 3-p to phosphatidoc acid to diacylglycerol to triacylglycerol(TAG)

Question 18

In which step of TAG synthesis phospfate is removed?

Answer 18

In converting phosphatidic acid into diacylglycerol

Question 19

Adipose tissue stores fatty acids(FA) only when ………..

Answer 19

Glycolysis is activated which means in fed state which means when insulin is increased in blood

Question 20

When doe the adipose tissue storage of TAG increases?

Answer 20

After a meal whan insulin levels are elevated in blood

Question 21

In ………. State, in adipose tissue, glucose is converted into glycerol 3-p

Answer 21

Fed state

Question 22

During fasting state a decrease in insulin and an increase in glucagon cause ………

Answer 22

cAMP levles rise in adipose tissue.

The rising of cAMP stimulates lipolysis.

Question 23

…………. Stimulates lipolysis by acting as a 2nd massenger.

Answer 23

Glucagon

Question 24

What enzyme acts in fasting state that comverts TAG into glycerol and FA ?

Answer 24

Hormone Sensitive Lipase (HSL)

Question 25

What enzyme works to degrade trigleceride ?

Answer 25

(HSL) hormone sensitive lipase enzyme

Question 26

What is Triacylglycerol (TAG) hydrolysis?

Answer 26

When TAG is degraded to glycerol and FA. by using the enzyme HSL HSL removes ester bonds between glycerol and FA

Question 27

Lipase degrades TAG into …………. Which is degraded again by using lipase into ……… which again degraded into ………. By using lipase that breaks the ester bonds between glycerol and FA.

Answer 27

Diacylglycerol 2-monoacylglycerol Glycerol

Question 28

Free FA which is removed while degradation by using enzyme lipase (HSL) are used for what?

Answer 28

These free FA breaks down into acetyle co-A , then it inters the citric cycle where these are oxidized. So oxidation happens to free FA

Question 29

What happens to free glycerol that is produced from degradation of TAG ?

Answer 29

Goes to glucogenesis for energy

Question 30

Compound lipods are devided into

Answer 30

1. Phospholipids which are devided into 2 types ( glycerophospholipids and sphingophospholipids ) 2. Glycolipids

Question 31

Glycolipids examples

Answer 31

Cerebrosides ( for brain) | Gangliosides ( for ganglions)

Question 32

Examples of glycerophospholipods

Answer 32

Lecithins ( surfactant) Cephalins ( blood clotting) Inositol ( hormone action)

Question 33

What is lecithins and what is it used for?

Answer 33

It is a type of glycerophospholipids , and it is used as a surfactant

Question 34

What is is cephalins and what is it used for?

Answer 34

It is a glycerophospholipid and is used for blood clotting

Question 35

What is is inositol and what is it used for?

Answer 35

It is a glycerophospholipid and is used as a hormone

Question 36

What is is sphingomyelin and what is it used for?

Answer 36

It is a sphingophospholipid and it is used in the nervous system , myelin sheets, brain and also in lungs

Question 37

What does a simple lipid contain?

Answer 37

Glycerol + 3 FA

Question 38

What does a phospholipid contain ?

Answer 38

Glycerol+ 2FA + phosphate + nitrogen base

Question 39

What does a sphingolipid contain?

Answer 39

Sphingosine + FA + p + nitrogen base

Question 40

Where are glycerophospholipids synthesized?

Answer 40

Smooth endoplsmic reticulum

Question 41

Perecursors of glycerophospholipids ?

Answer 41

Phosphatidic acid and 1,2 diacylglyceeol (DAG)

Question 42

Is glycerophospholipids an intermidiate in TAG metabolism?

Answer 42

Yes

Question 43

Is phosphatidic acid an intermidiate for TAG ?

Answer 43

Yes