Lipids

Question 1

Lipids is a heterogeneous group of _____ organic molecules.

Answer 1

Water-insoluble (hydrophobic)

Question 2

Lipids are a major source of energy with 1 gram equal to ___ kcal.

Answer 2

9

Question 3

Fatty acid double bonds almost always have the cis configuration and this puts a__° bend in the hydrocarbon chain of unsaturated fatty acids.

Answer 3

30 degree

Question 4

Rank the melting point from highest to least: Lauric acid, Myristic acid, Palmitic acid, Stearic acid.

Answer 4

(High to Low) Stearic acid (70), Palmitic acid (63), Myristic acid (52), Lauric acid (44)

Question 5

_____acid is the precursor of arachidonic acid, the substrate for prostaglandin synthesis.

Answer 5

Linoleic

Question 6

_____ acid is the precursor for other omega-3 fatty acids such as EPA and DHA.

Answer 6

a-linoienic

Question 7

Almost all fatty acids present in mammalian tissues are of the _____.

Answer 7

Straight-chain variety

Question 8

Phytanic acid oxidase removes the methyl groups, but a genetic disease affecting this enzyme leads to _____ disease.

Answer 8

Refsum’s

Question 9

_____ are fatty acid triesters of glycerol.

Answer 9

Triacylglycerols

Question 10

1g of carb yields ___ kcals

Answer 10

4

Question 11

1g of protein yields___kcals

Answer 11

4

Question 12

•Sphingomyelinase deficiency
• Enlarged liver and
spleen filled with lipid
• Severe mental retardation and neurodegeneration
• Death in early childhood (Type A)
What disease is this?

Answer 12

Niemann-Pick Disease

Question 13

Ceramidase cleaves the ___ linkage of ceramide.

Answer 13

Amide

Question 14

_____are most prevalent in the neuronal cell membranes of the brain.

Answer 14

Galactocerebrosides

Question 15

_____ occur more frequently in the membranes of other tissues.

Answer 15

Glucocerebrosides

Question 16

What is the precursor for Glucocerebrosides, Sulfatide, and Sphingomyelin?

Answer 16

Ceramide

Question 17

Cholesterol has a fused ___ring planar system.

Answer 17

4

Question 18

_____ is a precursor of bile acids, steroid hormones and vitamin D.

Answer 18

Cholesterol

Question 19

Cholesterol is classified as a _____ because of its OH group, and this polar OH group gives it weak amphiphilic character.

Answer 19

Sterol

Question 20

Order the lipoproteins from greatest density to least: Chylomicrons, VLDL, LDL, HDL

Answer 20

(Most dense to least)

HDL, LDL, VLDL, Chylomicrons

Question 21

Order the lipoproteins from larges to smallest: HDL, LDL, VLDL, Chylomicrons.

Answer 21

(Largest to smallest)

Chylomicrons, VLDL, LDL, HDL

Question 22

Digestion begins in the _____ where lingual and gastric lipase removes short and medium chain fatty acids from triacylglycerol

Answer 22

Stomach

Question 23

Chylomicrons are released by exocytosis and they give the lymph a milky appearance which is called _____.

Answer 23

Chyle