Lipid Classification

Question 1

What is amphipathic?

Answer 1

Having both hydrophilic and hydrophobic components, aka fatty acids

Question 2

What is the hydrophobic structure of FAs?

Answer 2

Hydrocarbon chains

Question 3

What is the hydrophilic structure of FAs?

Answer 3

Terminal carboxyl group

Question 4

What is the pKa of the terminal carboxyl group of FAs?

Answer 4

About 4.8

Question 5

At physiological pH, what happens to the carboxyl group of FAs?

Answer 5

The -COOH ionizes to -COO(-) and becomes anionic and hydrophilic

Question 6

What is LCFA?

Answer 6

Long chain fatty acids

Question 7

Since LCFAs are hydrophobic, how are they moved through circulation?

Answer 7

Must be in association with a protein for circulation solubility

Question 8

Saturated FAs

Answer 8

No double bonds

Question 9

Unsaturated FAs

Answer 9

Carbons have 1 or more double bonds

Question 10

More than one double bond in FA

Answer 10

Polyunsaturated

Question 11

Double bonds of FAs are in what formation?

Answer 11

Cis formation

Question 12

The Cis formation causes FAs to do what?

Answer 12

Bend or kink

Question 13

Cis formations are placed at…

Answer 13

3 carbon intervals

Question 14

Melting point/fluidity and Double bonds

Answer 14

The more double bonds, the lower the Tm and higher the fluidity

Question 15

Increasing chain length and Tm/fluidity

Answer 15

Increases Tm and decreases fluidity

Question 16

Therefore LCFA have:

Answer 16

High Tm due to chain length

High fluidity due to double bonds

Question 17

Carbon 1, 2, 3, 4 of FAs

Answer 17

Carbon 1 in the carboxyl carbon

Carbon 2 is the alpha carbon, attached to the carboxyl group

Carbon 3 is the beta carbon

Carbon 4 is the gamma carbon

Question 18

Terminal methyl group carbon is the..

Answer 18

w-carbon

Question 19

Naming of FAs can start at the carboxyl carbon or w-carbon depending on the:

Answer 19

“Terminal” double bond

Question 20

example of a w-6 FA

Answer 20

Arachidonic acid 20:4(4,8,11,14)

Question 21

What does 20:4(5,8,11,14) means?

Answer 21

Unsaturated

20 carbons

4 double bonds

Double bonds at 5,8,11,14 C’s

Question 22

2 FAs that humans cannot synthesize

Answer 22

Linoleic acid and alpha-Linoleic acid

Question 23

Linoleic acid

Answer 23

w-6 FA

18:2(9,12)

Question 24

alpha-Linoleic acid

Answer 24

w-3 acid

18:3(9,12,15)

Question 25

Arachidonic acid becomes essential IF? And why?

Answer 25

If Linoleic acid is deficient in the diet Because Linoleic acid is a precursor for other shorter w-6 FAs

Question 26

What FA is a substrate for prostaglandin synthesis?

Answer 26

Arachidonic acid

Question 27

What is a precursor for w-3 FAs?

Answer 27

Alpha-Linoleic acid

Question 28

What FA is important for growth and development?

Answer 28

Alpha-Linoleic acid

Question 29

4-10 carbons

Answer 29

Short and medium chain length FAs

Question 30

16-22 carbons

Answer 30

LCFAs

Question 31

More than 22 carbons

Answer 31

Very long chain FAs

Question 32

Where are FAs produced?

Answer 32

Cytosol

Question 33

2 forms of FAs

Answer 33

Free FAs Fatty acyl esters

Question 34

Unesterified FAs

Answer 34

Free FAs

Question 35

Esterified FAs

Answer 35

Fatty acyl esters

Question 36

Low level concentrations of FAs are found in

Answer 36

Most tissues, not including blood

Question 37

High level concentrations of FAs are found in blood serum during

Answer 37

fasting

Question 38

Albumin is important for FAs, how?

Answer 38

Transport of LCFAs in blood serum

Question 39

When will FAs come from TAGs? And where?

Answer 39

During fasting, and from adipose tissue

Question 40

Point of origin for FAs

Answer 40

From TAGs in adipose tissue From circulating lipoproteins (or liver/GI)

Question 41

Can most tissues take up free FAs?

Answer 41

Yes

Question 42

Free FA functions

Answer 42

Structural components of membrane conjugation to proteins for membrane anchoring properties Oxidized to provide energy (liver and muscle) Precursors for hormone-like prostaglandins

Question 43

Precursors of fatty acyl esters can be used to form

Answer 43

Complex molecules, like TAG

Question 44

What are fatty acyl esters stored?

Answer 44

Adipose tissue, as TAG

Question 45

What serves as the major energy reserve for the body?

Answer 45

fatty acyl esters

Question 46

Most plasma fatty acids are:

Answer 46

Fatty acyl esters (90%)

Question 47

Fatty acyl esters are contained in lipoprotein particles such as:

Answer 47

TAG cholesteryl esters phopholipids