Lipids

Question 1

Lipids (from the Greek ____,___)

Answer 1

lipos, fat

Question 2

constituents of plants or animals that are characterized by their solubility properties.

Answer 2

Lipids

Question 3

In particular, lipids are insoluble in water but are soluble in nonpolar organic solvents, such as____

Answer 3

diethyl ether.

Question 4

Lipids can be extracted from ____and____ by organic solvents.

Answer 4

cells and tissues

Question 5

This solubility property distinguishes lipids from three other major classes of natural products

Answer 5

carbohydrates, proteins, and nucleic acids

Question 6

Fats and oils are triesters of glycerol and are called

Answer 6

triglycerides

Question 7

When we boil a fat or oil with alkali and acidify the resulting solution, we obtain glycerol and a mixture of fatty acids. The reaction is called

Answer 7

saponification

Question 8

There are two types of triglycerides

Answer 8

simple triglycerides & mixed triglycerides

Question 9

which are highly unsaturated, are converted into solid vegetable fats by catalytically hydrogenating some or all of the double bonds

Answer 9

Vegetable oils

Question 10

illustrated by the hydrogenation of glyceryl trioleate to glyceryl tristearate.

Answer 10

hardening

Question 11

made by hydrogenating cottonseed, soybean, peanut, or corn oil until the desired butter-like consistency is obtained. The product may be churned with milk and artificially colored to mimic butter’s flavor and appearance.

Answer 11

margarine

Question 12

constitute about 40% of cell membranes, the remaining 60% being proteins

Answer 12

Phospholipids

Question 13

Phospholipids are related structurally to fats and oils, except that one of the three ester groups is replaced by a

Answer 13

phosphatidylamine

Question 14

The fatty acid portions are usually

Answer 14

palmityl, stearyl, or oleyl

Question 15

Phospholipids arrange themselves in bilayers in membranes, with the two hydrocarbon “____” pointing in and the polar phosphatidylamine ends constituting the membrane surface.

Answer 15

tails

Question 16

play a key role in biology, controlling diffusion of substances into and out of cells

Answer 16

Membranes

Question 17

differ from fats and oils in that they are simple monoesters. The acid and alcohol portions of a wax molecule both have long saturated carbon chains.

Answer 17

Waxes

Question 18

Waxes are more ____, _____, and ____ than fats

Answer 18

brittle,harder, and less greasy

Question 19

They are used to make _____, _______, _____, and __________, as well as candles and phonograph records

Answer 19

polishes, cosmetics, ointments, and other pharmaceutical preparations

Question 20

True or false

In nature, waxes coat the leaves and stems of plants that grow in arid regions, thus reducing evaporation

Answer 20

True

Question 21

True or false

Similarly, insects with a high surface-area-to-volume ratio often have a coating of a natural protective wax.

Answer 21

True

Question 22

Lipids are hydrophobic means?

Answer 22

hydro= "water"
phobic= "fear of"

Question 23

Olive oil gives ___% oleic acid

Answer 23

83%

Question 24

gives 43% palmitic acid and 43% oleic acid, with lesser amounts of stearic and linoleicacids

Answer 24

Palm oil

Question 25

gives at least 14 different fatty acids on hydrolysis and is somewhat exceptional in that about 9% of these acids have fewer than 10 carbon atoms

Answer 25

Butterfat

Question 26

What is it that makes some triglycerides solids (fats) and other liquids (oils)?

Answer 26

- The distinction is clear from their composition. Oils contain a much higher percentage of unsaturated fatty acids than do fats.

Question 27

T or F | The melting points of unsaturated fatty acids are appreciably "higher" than those of saturated acids

Answer 27

F (lower)

Question 28

T or F The same difference applies to trigycerides: The more double bonds in the fatty acid portion of the triester, the "lower" its melting point.

Answer 28

T

Question 29

When a fat or oil is heated with alkali (e.g.,NaOH), the ester is converted to glycerol and the salts of fatty acids. The reaction is illustrated here with the saponification of_____?

Answer 29

glyceryl tripalmitate

Question 30

Categories of Lipids?

Answer 30

Triglycerides Phospholipids Steroids Waxes

Question 31

solid at room temperature used by animals?

Answer 31

fats

Question 32

liquid at room temperature used by plants?

Answer 32

oils

Question 33

hydrophilic head means

Answer 33

"water- loving"

Question 34

hydrophobic tail means

Answer 34

"water-hating"

Question 35

Non-polar & repel water

Answer 35

waxes

Question 36

are extremely important, mainly because of their unique properties in regard to water

Answer 36

Phospholipids

Question 37

are similar to triglycerides in that they contain glycerol & two fatty acids

Answer 37

Phospholipids

Question 38

are lipids because they are hydrophobic and insoluble in water, but they do not resemble lipids since they have a structure composed of four fused rings.

Answer 38

steroids

Question 39

the most common steroid and is the precursor to vitamin D, testosterone, estrogen, progesterone, aldosterone, cortisol, and bile salts.

Answer 39

Cholesterol

Question 40

steroids sources?

Answer 40

- Cholesterol (most common) - Testosterone (male steroid hormone) - Estrogen (who use anabolic steroids for bodybuilding) - Vitamin D(known for its important role in regulating body levels) - cortisone (type of anti-inflammatory drug) - plasma membrane ( lipophilic suggesting they intercalate into the bilayer of target cell plasma membranes,)

Question 41

Only single carbon to carbon bonds known as_____

Answer 41

saturated fatty acid

Question 42

have one to several double bonds

Answer 42

unsaturated fatty acid

Question 43

Lipids are classified by their___

Answer 43

structure

Question 44

lipids do not dissolve in water because they are

Answer 44

non-polar

Question 45

Saturated fats have-

Answer 45

- single bond - straight structure - solidity at room temperature

Question 46

A lipid is a polymer that is made of what kind of polymer?

Answer 46

fatty acids and a glycerol

Question 47

A phospholipid bilayer comprises what part of cell?

Answer 47

cell membrane

Question 48

The C-O-O-H on the end of a fatty acid structure is called a

Answer 48

carboxyl group

Question 49

Lipids are made up of carbon, hydrogen and ____

Answer 49

oxygen

Question 50

Triglyceride is made up of ______backbone

Answer 50

glycerol

Question 51

A fatty acid consists of a hydrocarbon chain, methyl end and _______group

Answer 51

carboxyl group

Question 52

how do lipids function for cells and organisms?

Answer 52

store energy