Lipids

Question 1

Hydrophobicity of fatty acids is due to

Answer 1

Predominant hydrocarbon chain

Question 2

What are simple and complex lipid

Answer 2

Simple lipids are those that yields two types of products on hydrolysis.
Complex lipids yields two or three types of products on hydrolysis.

Question 3

Fatty acids

Answer 3

Simplest form of lipids. Have a long chain hydrocarbon with one carboxylic group. It is amphipathic in nature.

Question 4

Essential fatty acids

Answer 4

Fatty acids that are not synthesized in the human body. Example linoleate and linolenate.

Question 5

What affects the melting point of fatty acids

Answer 5

The longer the chain, the higher the melting point. Greater the number of double bonds the lower the melting point.

Question 6

How does the chain length affects the solubility in water

Answer 6

The longer the fatty acyl chain and fewer the double bonds the lower is the solubility in water

Question 7

Triacylglycerol

Answer 7

They have three fatty acid chain and one glycerol.
Non polar and neutral and hydrophobic in nature

Question 8

Major storage form of lipids

Answer 8

Triacylglycerol

Question 9

Saponification

Answer 9

Hydrolysis of triacylglycerol with an alkali such as NaOH or KOH

Question 10

Waxes. Eg.

Answer 10

Esters of fatty acids.
Beeswax from bees have triacontanyl palmitate.
Carnauba wax from Copernicia prunifera

Question 11

Ether glycerophospholipid

Answer 11

Possesses an ether linkage at C1 carbon of glycerol. Eg. Platelet accumulating factor

Question 12

Plasmalogen

Answer 12

Ether glycerophospholipid in which alkyl moiety is cis a,b unsaturated

Question 13

Steroid

Answer 13

Complex derivatives of triterpenes. Composed of four fused rings called steroid nucleus. Sterols are amphipathic in nature.

Question 14

Cholesterol

Answer 14

Acts as a precursor for steroid hormones and bile salts. Not found in plants and fungi. 27 carbon compound has four rings and C3 has a OH group present. It keeps membrane fluid

Question 15

Eicosanoids

Answer 15

Signalling molecules act locally.
Two types, prostanoids and leukotrienes.

Question 16

Pathways of prostanoids and leukotrienes

Answer 16

Prostanoids - cyclooxygenase pathway
Eicosanoids - Lipoxygenase pathway

Question 17

Prostanoids include?

Answer 17

Prostaglandins, prostacyclin and thromboxanes

Question 18

Prostaglandins

Answer 18

Identified in human semen. All mammalian cells except RBCs produce them. Derivatives of prostanoic acid. Precursor arachidonic acid.

Question 19

Precursor of prostaglandins and thromboxanes

Answer 19

Prostaglandins H2

Question 20

Function of prostaglandins

Answer 20

Uterine contraction
Vasodilator
Low BP
Inflammation
Pain

Question 21

Inhibitor of prostaglandins

Answer 21

Nonsteroidal anti inflammatory drugs

Question 22

Thromboxanes

Answer 22

In blood platelets. Helps in clotting and vasoconstrictor.

Question 23

Prostacyclin

Answer 23

Formed by PGH2 by enzyme prostacyclin synthase. Abundant in endothelial cells. Vasodilator and inhibits platelet aggregation

Question 24

Leukotrienes

Answer 24

Derived from arachidonic acid. Do not have a ring. Occurs in leukocytes. Increases intracellular calcium. Decreases intracellular cAMP

Question 25

Prostaglandins synthesis is increased by?

Answer 25

Activating phospholipase by angiotensin II

Question 26

Plasma Lipoprotein

Answer 26

Protein with a lipid in human plasma

Question 27

Lipoprotein types

Answer 27

Low density lipoprotein
Very low density lipoprotein
Chylomicron
Intermediate density lipoprotein
High density lipoprotein

Question 28

Lipoprotein structure

Answer 28

Core having neutral lipids such as triacylglycerol and cholesterol esters. Coated with monolayer of phospholipids and cholesterols with protein (apolipoprotein) and cholesterol.

Question 29

Relationship of molecular mass and density

Answer 29

Inversely proportional

Question 30

Transport of exogenous triacylglycerol

Answer 30

Chylomicron

Question 31

Transport of endogenous triacylglycerol

Answer 31

VLDL