LIPIDS Intro REVIEWER

Question 1

What are Lipids?

Answer 1

✅Fats
✅ Stored chemical energy (9kcal/g)

Question 2

Functions of Lipids

Answer 2

1. Covering / protection vital organs
2. Insulation
3. Prevention of excessive heat loss
4. Major component in cell membrane:
   👉🏼 phospholipid, glycolipids, and cholesterol
5. Component in hormones (chem’l msgr; cholesterol derivatives)

Question 3

Characteristics of Lipids:

Answer 3

✅ based on solubility
(more soluble in organic solvents- dichloromethane vs water)

✅ an organic compound in living organisms that is insoluble (or sparingly soluble) in water but soluble in nonpolar organic solvents

Question 4

Structure of Lipids:

Answer 4

ester, amides, alcohol

Question 5

Examples:

Answer 5

fat, biological wax, steroids, glycerophospholipid, sphingophospholipid, sphingoglycolipid

fatty acids (except cholesterol, bile acids and steroid hormones)

Question 6

5 classes of Lipids (based on fxn)

Answer 6

1. Energy
2. Membrane lipids
3. Emulsification lipids
4. Messenger lipids
5. Protective coating lipids

Question 7

Energy

Answer 7

Storage lipids (triacyglycerols)

Question 8

Membrane lipids

Answer 8

phospholipids, sphingoglycolipids, cholesterol

Question 9

Emulsification lipids

Answer 9

bile acids

Question 10

Messenger lipids

Answer 10

steroid hormones, and eicosanoids

Question 11

Protective coating lipids

Answer 11

biological waxes

Question 12

Lipid Organization based on Structural Relationship

Lipids 
↙️↘️

Answer 12

Lipids
↙️ ↘️
Fatty acids Steroids

Question 13

Fatty acids
↙️↙️ ↘️↘️

Answer 13

Fatty acids

1.Triglycerides
2. Phosphoglycerides
3. Waxes
4. Sphingolipids

Question 14

Sphingolipids
↙️↘️

Answer 14

Sphingolipids
↙️ ↘️
Sphingomyelins Glycolipids

Question 15

Glycolipids
↙️↘️

Answer 15

Glycolipids
↙️ ↘️
Cerebrosiders Gangliosides

Question 16

What is Fatty acids?

Answer 16

✅ -COOH ; Monocarboxylic acids
✅ structural components of fats, oils, and all other categories of lipids, except steroids

Question 17

categorization of fatty acids

Answer 17

✅ Long chain fa (12-26C)
✅ Medium chain fa (8-10C)
✅ Short chain fa (4-6C)

Rarely found free in nature (forms complexes with other lipid molecules)

Fa acids isolated from naturally occurring fats

Question 18

3 characteristics:

Answer 18

1. Unbalanced C chain
2. Even # of C (12-20)
3. Has C-C, when present, are in vid configuration

Question 19

types of fa :

Answer 19

Saturated and Unsaturated

Question 20

Some Common Fatty Acids Found in Natural Fats

Answer 20

lauric acid
myristic acid
palmitic acid
palmitoleic acid
stearic acid
oleic acid
linoleic acid
a- linoleic acid
arachidonic acid

Question 21

linoleic and a- linoleic acids

Answer 21

✅ essential fatty acids
✅ must be obtain form diets
✅ The body uses linoleic acid to synthesize many of the other unsaturated fatty acids: ex. arachidonic acid (precursor for prostaglandins)
✅ necessary for the efficient transport and metabolism of cholesterol
✅ average daily diet ➡️ 4-6 g of the essential fatty acids

Question 22

SFA

Answer 22

saturated fa

Question 23

MUFAs

Answer 23

monounsaturated fa

Question 24

PUFAs

Answer 24

polyunsaturated fa

Question 25

SFA description:

Answer 25

✅C-C chain is single bond ex: hexadecanoic acid (IUPAC); palmatic acid (CN); CH3-(CH4)14- COOH or COOH /\/\/\/\/\/\/\/\/\/\/\/\/

Question 26

MUFA description:

Answer 26

✅ fa with C chain with one C-C double bond ✅ cis ➡️ configuration of about the C-C biochemically important MUFA; ➡️ 30° bend in the chain (affects the physical prop of the fa) ex: cis-9-octadecenoic acid (IUPAC); oleic acid (CN) CH3-(CH2)7-CH-CH-(CH2)7- COOH • 500 fa isolated both MUFA and PUFA

Question 27

PUFA description:

Answer 27

✅ fa with 2 or more C-C ✅ biochemically important PUFA ➡️ 6C-C are found ex: cis, cis-9, 12-octadecadienoic acid (IUPAC); linoleic acid (CN)

Question 28

Unsaturated fa and double bond position shorthand:

Answer 28

shorthand: 2 numbers separated by a colon (#C:#C-C) ex: 18: 0; 18: 2

Question 29

Unsaturated fa and double bond position specification of C-C position add 🔼 followed by ____________ where the double bond is found ___________

Answer 29

specification of C-C position add 🔼 followed by # (superscript) where the double bond is found (COOH is always at C1 ex: 18:3 ( 🔼^9,12,15)

Question 30

MUFAs are ____ acids

Answer 30

MUFAs are 🔼^9 acids

Question 31

PUFAs first 2 additional double bonds are usually at 🔼— and🔼—

Answer 31

PUFAs first 2 additional double bonds are usually at 🔼^12 and🔼^15 exception: arachidonic acid ➡️ 20:4. (🔼^5,8,11,14)

Question 32

Families of unsaturated fa description:

Answer 32

✅ double bond positioning (relatively to methyl or noncarboxylic end) is determined using lower case omega ex: omega-3 fatty acid (20:5) 1 3 — — — — COOH \| \/ \/ \/ \/\/ Omega-6 fa ➡️ 14:1 ➡️ 18:2 ➡️ 20:3

Question 33

fa of biological importance •saturated 1. ___ acid (_:_) 2. ___ acid (_:_) 3. ___ acid (_:_) 4. ___ acid (_:_) 5. ___ acid (_:_)

Answer 33

1. Lauric acid (12:0) 2. Myristic acid (14:0) 3. Palmitic acid (16:0) 4. Stearic acid (18:0) 5. Arachidic acid (20:0)

Question 34

fa of biological importance •MUFA 1. ___ acid (_:_ 🔼^- w-_) 2. ___ acid (_:_ 🔼^- w-_)

Answer 34

1. Palmitoleic acid (16:1 🔼^9 w-7) 2. Oleic acid (18:1 🔼^9 w-9)

Question 35

fa of biological importance •PUFA 1. ___ acid (_:_ 🔼^- w-_) 2. ___ acid (_:_ 🔼^- w-_) 3. ___ acid (_:_ 🔼^- w-_) 4. ___ acid (_:_ 🔼^- w-_) 5. ___ acid (_:_ 🔼^- w-_)

Answer 35

1. Linoleic acid (18:2 🔼^9,12 w-6) 2. Linoleic acid (18:3 🔼^9,12, 15 w-3) 3. Arachidonic acid (20:4 🔼^5,8,11,14w-6) 4. EPA/eicosapentaenoic acid (20:5 🔼^ 5,8,11,14,17 w-3) 5. DHA/ docosahexaenoic acid (22:6 🔼^4,7,10,13,16,19 w-3)

Question 36

Physical properties of fa:

Answer 36

• basis: length and degree of unsaturation of the fa C chain

Question 37

Characteristics of fa:

Answer 37

• low solubilities in water • Dec with inc #C • at 30°C, lauric acid (12:0) has a water solubility of 0.063 g/L; stearic acid (18:0) a solubility of 0.0034 g/L • water solubility of fa is a direct fxn of C chain length (inversely proportional) • SCFA - slightly soluble (due to polar COOH grp) •LCFA - insoluble in Walter (hydrocarbon dominates over carbonyl grp)

Question 38

MP basis:

Answer 38

basis: C chain length and degree of unsaturation

Question 39

MP C length is _______ proportional to MO due to greater SA and intermolecular attraction.

Answer 39

directly proportional

Question 40

SFA > MUFA or PUFA (Double bonds _____ molecular attractions between C chain; ______proportional- Low MP with high or more C-C) •cis config in MUFA and PUFA creates ____ (prevents unsat fa from packing together as tightly as SFA) • SFA - ____ at room temp • MUFA or PUFA - _____ at room temp

Answer 40

Double bonds decrease molecular attractions between C chain; inversely proportional- Low MP with high or more C-C •cis config in MUFA and PUFA creates bends (prevents unsat fa from packing together as tightly as SFA) • SFA - solid at room temp • MUFA or PUFA - liquid at room temp