Ch 17 Lipids

Question 1

biomolecules that contain fatty acids or a steroid nucleus

Answer 1

Lipids

Question 2

soluble in organic solvents but not in water.

Answer 2

Lipids

Question 3

an important feature in cell membranes, fat-soluble vitamins, and steroid hormones

Answer 3

Lipids

Question 4

esters that can be hydrolyzed to give fatty acids and other molecules

Answer 4

sphingolipids

Question 5

Triacylglycerols and glycerophospholipids contain the alcohol ___

Answer 5

glycerol

Question 6

Sphingolipids contain the amino alcohol ___

Answer 6

sphingosine

Question 7

Steroids, which have a completely different structure, do not contain ____ and cannot be hydrolyzed. They are characterized by the steroid nucleus of four fused carbon rings

Answer 7

fatty acids

Question 8

3 cyclohexanes and 1 cyclopentane

Answer 8

steroid

Question 9

Long carbon chain with a carboxyl group

Answer 9

fatty acids

Question 10

long, unbranched carbon chains with a carboxylic acid group at the end

Answer 10

Fatty acids

Question 11

typically 12–18 carbon atoms long.

Answer 11

Fatty acids

Question 12

Fatty acids are ___ when they do NOT contain C=C double bonds in the carbon chain

Answer 12

saturated

Question 13

Fatty acids are ____ when they contain C = C double bonds in the carbon chain.

Answer 13

unsaturated

Question 14

Common saturated fatty acids

Answer 14

lauric (coconut)

myristic (nutmeg)

palmitic (palm)

stearic (animal fat)

Question 15

Fatty acids can be monounsaturated, with only one double C = C bond in the carbon chain. Examples?

Answer 15

palmitoleic

oleic

Question 16

Almost all naturally occurring unsaturated fatty acids have one or more ___ double bonds

Answer 16

cis

Question 17

Saturated fatty acids

Answer 17

contain only single C — C bonds and fit close together in a regular pattern, with strong dispersion forces between carbon chains

Question 18

In unsaturated fatty acids, __double bonds cause the carbon chain to bend or kink, giving the molecules an irregular shape and thus allowing fewer interactions between molecules

Answer 18

cis

The reduced interactions in fatty acids with cis bonds reduce the melting point of the molecules.

Question 19

Humans cannot synthesize sufficient amounts of polyunsaturated fatty acids such as ___

Answer 19

linoleic acid, linolenic acid, and arachidonic acid

considered essential

Question 20

are hormone-like substances produced in small amounts in most cells

Answer 20

Prostaglandins

differ by the substituents attached to the five-carbon ring.

Question 21

are also known as eicosanoids, formed from arachidonic acid, a polyunsaturated fatty acid with 20 carbon atoms

Answer 21

Prostaglandins

Question 22

have many functions, such as lowering or raising blood pressure and stimulating contraction and relaxation of the smooth muscle of the uterus

Answer 22

Prostaglandins

Question 23

prostaglandin E (PGE) has a ___ group on carbon 9

Answer 23

ketone

Question 24

prostaglandin F (PGF) has a ___ group on carbon 9

Answer 24

hydroxyl

Question 25

When tissues are injured, ___ is converted to prostaglandins that produce inflammation and pain in the area

Answer 25

arachidonic acid

Question 26

Nonsteroidal anti-inflammatory drugs (NSAIDs) block production of ___, decreasing pain and inflammation

Answer 26

prostaglandins

Question 27

esters of glycerol, a trihydroxy alcohol, and fatty acids

Answer 27

triacylglycerols

Question 28

formed when three hydroxyl groups of glycerol react with the carboxyl groups of three fatty acids

Answer 28

triacylglycerols

Question 29

named by changing glycerol to glyceryl and naming the fatty acids as carboxylates.

Answer 29

triacylglycerols

Question 30

The general formula of a triacylglycerol consists of three hydroxyl groups of glycerol forming ___ bonds with the carboxyl groups of three fatty acids

Answer 30

ester

Question 31

To name the fatty acid formed with three stearic acids, the name becomes glyceryl tristearate. The common name of this compound is ___.

Answer 31

tristearin

Question 32

___ are the major form of energy storage for animals

Answer 32

Triacylglycerols

Question 33

have higher melting points than do unsaturated fatty acids because they pack together more tightly. are usually found in animal fats, coconut oil, and palm oil

Answer 33

Saturated fatty acids

Question 34

double bonds in unsaturated fatty acids react with hydrogen gas to produce carbon–carbon single bonds hydrogen gas is bubbled through the heated oil typically in the presence of a nickel catalyst

Answer 34

hydrogenation reactions Commercial hydrogenation = the addition of hydrogen is stopped before all the double bonds in a liquid vegetable oil become completely saturated. the partial hydrogenation of a liquid vegetable oil changes it to a soft, semisolid fat.

Question 35

the more saturated a product the ___ its melting point.

Answer 35

higher

Question 36

Triacylglycerols are hydrolyzed (split by water) in the presence of strong acids such as HCl or H2SO4, or digestive enzymes called ____

Answer 36

lipases

Question 37

is the reaction of a fat with a strong base such as NaOH in the presence of heat splits triacylglycerols into glycerol and the salts of fatty acids is the process of forming “soaps” (salts of fatty acids).

Answer 37

Saponification

Question 38

gives solid soaps that can be molded into different shapes when mixed with NaOH gives softer, liquid soaps when mixed with KOH

Answer 38

Saponification

Question 39

The products of ester hydrolysis are glycerol and ____.

Answer 39

three fatty acids The polar glycerol is soluble in water, but the fatty acids with their long hydrocarbon chains are not.

Question 40

two fatty acids that form ester bonds with the first and second hydroxyl groups of glycerol. a hydroxyl group that forms an ester with phosphoric acid, which forms another phosphoester bond with an amino alcohol

Answer 40

Glycerophospholipids

Question 41

contains sphingosine instead of glycerol. contains a fatty acid, phosphate, and an amino alcohol.

Answer 41

Sphingomyelin

Question 42

Amino alcohols found in glycerophospholipids are?

Answer 42

choline, serine, and ethanolamine | ionized at pH 7.4

Question 43

two types of glycerophospholipids that are abundant in brain and nerve tissues. Also found in egg yolk, wheat germ, and yeast.

Answer 43

Lecithin and cephalin

Question 44

contain both polar and nonpolar regions that allow them to interact with polar and nonpolar substances have a polar head containing the ionized amino alcohol and phosphate portion, which is strongly attracted to water have a nonpolar hydrocarbon tail portion soluble only in nonpolar substances such as lipids

Answer 44

Glycerophospholipids

Question 45

contain both polar and nonpolar regions that allow them to interact with polar and nonpolar substances have a polar head containing the ionized amino alcohol and phosphate portion, which is strongly attracted to water have a nonpolar hydrocarbon tail portion soluble only in nonpolar substances such as lipids

Answer 45

Glycerophospholipids

Question 46

sphingosine, a long-chain amino alcohol that replaces glycerol an amide bond formed by the amine group on sphingosine to a fatty acid a hydroxyl group that forms an ester bond with phosphate, which forms another phosphoester bond to choline or ethanolamine.

Answer 46

Sphingomyelin

Question 47

Sphingomylelins are abundant in what?

Answer 47

the white matter of myelin sheath

Question 48

steroid nucleus consists of

Answer 48

three cyclohexane rings and one cylopentane ring, fused together. rings designated as A, B, C, and D. numbered carbon atoms beginning in ring A. two methyl groups at positions 18 and 19.

Question 49

has a hydroxyl group (— OH) on carbon 3 has a double bond between carbons 5 and 6 has methyl groups on carbons 10 and 13. has an alkyl chain at carbon 17

Answer 49

Cholesterol

Question 50

have polar and nonpolar regions that act like soaps to make fat soluble in water. help in absorption of cholesterol.

Answer 50

Bile salts

Question 51

Lipids are nonpolar and are made more soluble by combining them with glycerophospholipids and proteins to form water-soluble complexes called

Answer 51

lipoproteins

Question 52

surround nonpolar lipids with polar lipids and protein for transport to cells. are soluble in water because the surface consists of polar lipids

Answer 52

Lipoproteins

Question 53

chemical messengers that serve as a communication system for the body produced from cholesterol sex hormones adrenal corticosteroids

Answer 53

Steroid hormones

Question 54

Steroids, which have a completely different structure, do not contain fatty acids and cannot be ___. They are characterized by the steroid nucleus of four fused carbon rings.

Answer 54

hydrolyzed

Question 55

require a significant amount of energy and high temperatures to separate and melt.

Answer 55

saturated fatty acids

Question 56

Nonsteroidal anti-inflammatory drugs (NSAIDs) block production of ____, decreasing pain and inflammation. NSAIDs include?

Answer 56

prostaglandins naproxen (Aleve and Naprosyn), ketoprofen (Actron), and nabumetone (Relafen).

Question 57

A ___ is an ester of a long chain fatty acid and a long chain alcohol, each containing from 14 to 30 carbon atoms

Answer 57

wax

Question 58

Vegetable oils have ___ melting points because they have a higher percentage of unsaturated fatty acids than do animal fats

Answer 58

low

Question 59

The products of ester hydrolysis are glycerol and three fatty acids from?

Answer 59

triacylgyerol hydrolysis

Question 60

Phospholipids are a family of lipids similar in structure to triacylglycerols; they include

Answer 60

glycerophospholipids and sphingomyelin

Question 61

amino alcohol, phosphoric acid, glycerol, and two fatty acids comprise a typical?

Answer 61

The components of a typical glycerophospholipid

Question 62

In a ____, a polar “head” contains the ionized amino alcohol and phosphate, while the hydrocarbon chains of two fatty acids make up the nonpolar “tails.”

Answer 62

glycerophospholipid

Question 63

are produced by the adrenal glands located on the top of each kidney. include aldosterone, which regulates electrolytes and water balance by the kidneys. include cortisone, a glucocorticoid, which increases blood glucose level and stimulates the synthesis of glycogen in the liver

Answer 63

steroid hormones (adrenal corticosteroids)