Lipids Part 1

Question 1

Lipids

• 4 main groups

(Saturated and Unsaturated)

(Glycerol-containing Lipids)

(Sphingolipids,Steroids,Wax)

(Lipoproteins)

Answer 1

– Fatty Acids

– Glycerides

– Nonglyceride Lipids

– Complex Lipids

Question 2

Energy Source

– When oxidized, each gram of fat releases______ of energy, or more than twice the energy released by oxidation of a gram of carbohydrate

Answer 2

9 kcal

Question 3

Energy Storage

– In the form of ____in adipocytes

Answer 3

triglycerides (TAG)

Question 4

Cell Membrane Structural Components

(3) make up the basic structure of all cell membranes

Answer 4

– Phosphoglycerides, sphingolipids, and steroids

Question 5

BIOLOGICAL FUNCTIONS OF LIPIDS

• Hormones –_____ Hormones

• Vitamins – Lipid-soluble vitamins

• Vitamin Absorption – Dietary fat serves as a____ of the lipid-soluble vitamins

• Protection – fats as

• Insulation – subcutaneous fat

Answer 5

Steroid

(A,D,E, and K)

carrier

shock absorber

Question 6

• Are long-chain monocarboxylic acids

• Generally contain an even number of carbon atoms

Answer 6

FATTY ACIDS

Question 7

FATTY ACIDS

• Short-Chain Fatty Acids

• Medium-Chain Fatty Acids

• Long-Chain Fatty Acids

Answer 7

– Less than 6 carbons

– 6-10 carbons

– More than 12 carbons

Question 8

– Each C being “saturated” with H

Answer 8

Saturated Fatty Acids

Question 9

Sat. Fatty Acids

– General Formula:

Answer 9

CH3 (CH2 )nCOOH

Question 10

– Composed of at least one carbon-to carbon double bond

– Almost are in the cis configuration

Answer 10

Unsaturated Fatty Acids

Question 11

– Composed of one carbon-to-carbon double bond

Answer 11

Monounsaturated Fatty Acids (MUFA)

Question 12

– Composed of more than one carbon-to carbon double bond

Answer 12

Polyunsaturated Fatty Acids (PUFA)

Question 13

– are identified by position of the double bond nearest the methyl end (CH3 ) of the carbon chain; this is described as an omega number;

Answer 13

Polyunsaturated Fatty Acids (PUFA)

Question 14

– If PUFA has first double bond 3 carbons away from the methyl end =

Answer 14

omega 3 FA

Question 15

• If PUFA has 6 carbons from methyl end =

Answer 15

omega 6 FA

Question 16

– H’s on same side of the double bond; fold into a U-like formation; naturally occurring

Answer 16

cis-Fatty Acid

Question 17

– H’s on the opposite side of the double bond; occur in partially hydrogenated food

Answer 17

trans-Fatty Acid

Question 18

Fatty acids with double bonds before
the 9th carbon are

Answer 18

ESSENTIAL

Question 19

Fatty acids with no double bonds before the 9th carbon are

Answer 19

NONESSENTIAL

Question 20

Your body can form C=C double bonds after the 9th carbon

Answer 20

Nonessential

Question 21

– Fatty acids react with alcohols to form esters and water

Answer 21

Esterification

Question 22

are the products of the dehydration of a carboxylic acid and an alcohol.

Answer 22

Esters

Question 23

• Producing fatty acids from esters
• Opposite of esterification

Answer 23

Acid Hydrolysis

Question 24

– Is the base-catalyzed hydrolysis of an ester

Answer 24

Saponification

Question 25

– the product of this reaction, an ionized salt, is a soap

Answer 25

Saponification

Question 26

• Have a long uncharged hydrocarbon tail and a negatively charged terminus (the carboxylate terminus), they form micelles that dissolve oil and dirt particles

Answer 26

soap

Question 27

Reaction at the Double Bond (Unsaturated Fatty Acids) • Used in the food industry to convert polyunsaturated vegetable oils into saturated solid fats

Answer 27

Hydrogenation

Question 28

• Carried out to add hydrogen to some, but not all, double bonds in polyunsaturated oils • In this way liquid vegetable oils are converted into solid form (Crisco and margarine)

Answer 28

Partial Hydrogenation

Question 29

• Are lipid esters that contain the glycerol molecule and fatty acids

Answer 29

GLYCERIDES

Question 30

GLYCERIDES 2 classes

Answer 30

Neutral glycerides Phosphoglycerides

Question 31

Glycerides – nonionic and nonpolar – have polar region, the phosphoryl group, in addition to the nonpolar fatty acid tails

Answer 31

Neutral Glycerides Phosphoglycerides

Question 32

– Produce after the esterification of glycerol with a fatty acid

Answer 32

Neutral Glycerides

Question 33

Esterification of glycerides may occur at one, two, or all three positions, producing:

Answer 33

• Monoglycerides • Diglycerides • Triglycerides

Question 34

NONGLYCERIDE LIPIDS

Answer 34

Sphingolipids Steroids Cholesterol

Question 35

– Are lipids that are not derived from glycerol – Amphipathic and structural components of cellular membranes

Answer 35

Sphingolipids

Question 36

Derived from sphingosine (long chain, Ncontaining alcohol) 2 TYPES

Answer 36

Sphingolipids • Sphingomyelins • Glycosphingolipids

Question 37

– Located throughout the body, but are particularly important structural lipid components of ***nerve cell membranes*** – Found in abundance in the ***myelin sheath*** the surrounds and insulate cells of the CNS – Role is essential to ***proper cerebral function*** and ***nerve transmission***

Answer 37

Sphingomyelins

Question 38

– Include the cerebrosides, sulfatides, and gangliosides

Answer 38

Glycosphingolipids (Glycolipids)

Question 39

Are built on a ceramide backbone structure, which is a fatty acid amide derivative of sphingosine

Answer 39

Glycosphingolipids

Question 40

Cerebrosides – Are characterized by the presence of a single monosaccharide head group – found almost exclusively in the membranes of brain cells – Consists of ceramide joined to the monosaccharide galactose

Answer 40

Galactocerebroside

Question 41

Cerebrosides – Are characterized by the presence of a single monosaccharide head group – found in the membranes of macrophages – Consists of ceramide bonded to the hexose glucose

Answer 41

Glucocerebrosides

Question 42

– Contain the steroid nucleus (steroid carbon skeleton)

Answer 42

Steroids

Question 43

• known sterol, found in the membranes

Answer 43

Cholesterol

Question 44

– Amphipathic – Involved in the regulation of the fluidity of the membrane as a result of the nonpolar fused ring – Hydroxyl group is polar – Perhydrocyclopentanophenanthrene ring

Answer 44

Cholesterol

Question 45

________ • Can also exist in an esterified form called______, with the hydroxyl group conjugated by an ester bond to a fatty acid – No polar groups making them very hydrophobic

Answer 45

CHOLESTEROL cholesteryl ester,

Question 46

• Almost exclusively synthesized by animals, but plants do contain other sterols similar in structure to cholesterol • It is not readily catabolized by most cells, therefore, does not serve as a source of energy

Answer 46

CHOLESTEROL

Question 47

T or F Cholesterol can be a source of energy

Answer 47

False

Question 48

Cholesterol Can be converted in the liver to (2) – Promote fat absorption in the intestine by acting as detergent

Answer 48

primary bile acids (e.g. cholic acid) and chenodeoxycholic acid

Question 49

_______ – Are amphipathic derivatives of cholesterol – Synthesized in the liver and stored in the gallbladder (2)

Answer 49

Bile Salts • Cholate • Chenodeoxycholate

Question 50

Emulsifying agent – whose polar hydroxyl groups interact with water and whose hydrophobic regions bind to lipids

Answer 50

Bile salts

Question 51

Steroid Hormones

Answer 51

– Testosterone – Progesterone – Estrone, Estrogen, and its derivatives – Cortisone and Cortisol – Aldosterone

Question 52

– Derived from many different sources and have a variety of chemical compositions, depending on the source Long hydrocarbon tails – extremely hydrophobic – completely insoluble in water

Answer 52

Waxes

Question 53

• – protective coating for hair and skin (used in skin creams and ointments)

Answer 53

Lanolin - wax