Lipids Flashcards Preview

Biochemistry I > Lipids > Flashcards

Flashcards in Lipids Deck (52)
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1

What are 5 biological functions of lipids?

Storage of energy, membrane structure, signaling molecules, cofactors for enzymes, and antioxidants.

2

Fatty acids with C10 or higher saturated hydrocarbon chains form...

Waxy solids at room temperature.

3

Fatty acids with C9 or lower saturated or unsaturated hydrocarbon chains are...

Oily liquids at room temperature.

4

The pKa of the COOH group is...

Less than 5

5

At what pH are fatty acids fully ionized?

pH 7

6

Most natural fatty acids...

Have an even number of carbons and are unbranched.

7

Cis-double bonds affect...

The position o fatty acid tails, results in kinks or bends which equals less ordered packing.

8

Unsaturated fatty-acids melting points are...

Lower

9

Solubility and melting point of fatty acids are determined by...

Length of hydrocarbon chains and degree of saturation.

10

All naturally occurring double bonds have...

Cis configuration.

11

How do trans fatty acids form?

By partial hydrogenation of unsaturated fatty acids and cis-double bond isomerization to trans double bonds.

12

When all fatty acids in a triglycerol are the same...

Simple tracylglycerides

13

When the fatty acids in a triglycerol are different...

Complex triacylglycerides

14

Triacylglycerols/Triglycerides

Glycerol + 3 fatty acids.
Storage lipid, neutral.

15

Waxes

Storage lipid, non polar, do not contain glycerol.

16

How are waxes formed?

By a condensation reaction between long fatty acids and alcohol hydrocarbon chains.

17

Composition of glycerophospholipid

2 fatty acids and glycerol 3-phosphate backbone.

18

What type of bond is formed between the phosphate group of glycerophospholipids and the carbon backbone chain?

Phosphodiester bond.

19

What type of bond connects fatty acids and a carbon backbone (except in sphingolipids)?

Ester bonds.

20

How are glycerophospholipids formed?

Condensation reaction between two fatty acids and the chiral carbon of glycerol 3-phosphate.

21

Fatty acids linked to first hydroxyl in glycerophospholipids are generally...

Saturated.

22

Fatty acids linked to second hydroxyl in glycerophospholipids are generally...

Unsaturated.

23

Head group

Alcohol based compounds linked to phosphatidic acids.

24

Sphingolipids are which type of lipid?

Structural, polar.

25

Sphingolipids structure

Sphingosine backbone (long chain amino alcohol), a fatty acid at C2, and a polar head group.

26

How is a fatty acid attached to the backbone of a sphingolipid?

Amide linkage.

27

How are polar head groups connected to the sphingosine backbone of sphingolipids?

Phospho-ester linkage

28

Sphingomeylin is classified as...

A phospholipid

29

Glycosphingolipids determine...

Blood groups

30

Gangliosides

Third group bonded to sphingosine chain in sphingolipids is a sugar.