Chapter 9: Lipids and Biological Membranes

Question 1

Fats, oils, certain vitamins and hormones, and most nonprotein membrane components are

Answer 1

lipids

Question 2

Lipid molecules in the form of what are essential components of biological
membranes.

Answer 2

lipid bilayers

Question 3

Lipids containing hydrocarbon chains serve as what

Answer 3

energy stores

Question 4

Over half of the fatty acid residues of
plant and animal lipids are

Answer 4

unsaturated and polyunsaturated

Question 5

Bacterial fatty acids are rarely

Answer 5

polyunsaturated

Question 6

Fatty acid double bonds almost always have the what configuration

Answer 6

cis

Question 7

melting points to what
with the degree of unsaturation

Answer 7

decrease

Question 8

function as energy reservoirs in animals and are therefore their most abundant class of lipids even though they are not components of cellular membranes.

Answer 8

Triacylglycerols

Question 9

do written notes for slide 5

Question 10

are complex mixtures of triacylglycerols whose fatty acid compositions vary with the organism that produced them

Answer 10

Fats and oils

Question 11

are the major lipid components of biological membranes.

Answer 11

Glycerophospholipids

Question 12

Glycerophospholipids have what heads and what tail

Answer 12

nonpolar aliphatic (hydrocarbon)“tails” and polar phosphoryl-X“heads.”

Question 13

which can disrupt cell
membranes cell thereby losing cells

Answer 13

phospholipase A2

Question 14

are glycerophospholipids in which the C1 substituent of the glycerol moiety is linked via an α,β-unsaturated ether linkage rather than through an ester linkage

Answer 14

Plasmalogens

Question 15

The N-acyl fatty acid derivatives of sphingosine are known
as

Answer 15

ceramides

Question 16

The most common sphingolipids are

Answer 16

sphingomyelins
(also sphingophospholipids)

Question 17

is the major lipid of lung surfactant which prevents the collapse of the alveolar space.

Answer 17

Dipalmitoylphosphatidylcholine (DPPC)

Question 18

are ceramides with head groups that consist of a single sugar residue.

Answer 18

Cerebrosides

Question 19

are the most complex
glycosphingolipids.

Answer 19

Gangliosides

Question 20

are primarily components of cell-surface membranes
and constitute a significant fraction (6%) of brain
lipids

Answer 20

Gangliosides

Question 21

Their complex carbohydrate head groups, which extend
beyond the surfaces of cell membranes, act as
specific receptors for certain pituitary glycoprotein hormones.

Answer 21

Gangliosides

Question 22

Disorder of ganglioside
breakdown is responsible for hereditary

fatal neurological deterioration in early childhood.

Answer 22

Tay-Sachs disease

Question 23

which is the most abundant steroid in animals

Answer 23

cholesterol

Question 24

is a major component of animal plasma membranes and its fused ring system provides it with greater rigidity than other lipids.

Answer 24

cholesterol

Question 25

is the metabolic precursor of steroid hormones in mammals.

Answer 25

Cholesterol

Question 26

affects carbohydrate, protein, and lipid metabolism.

Answer 26

Cortisol

Question 27

regulate the excretion of salt and water by the kidneys.

Answer 27

Aldosterone

Question 28

Impaired adrenocortical function

Answer 28

Addison's disease

Question 29

decreased amounts of glucose in the blood)

Answer 29

hypoglycemia

Question 30

Conversely, adrenocortical hyperfunction, which is often caused by a tumor of the adrenal cortex, results in

Answer 30

Cushing's syndrome

Question 31

increased amount of glucose in the blood)

Answer 31

hyperglycemia

Question 32

is male sex hormone,

Answer 32

Testosterone

Question 33

is female sex hormone

Answer 33

estrogen

Question 33

is nonenzymatically formed in the skin of animals through the photolytic action of UV light

Answer 33

Vitamin D

Question 34

is a lipid synthesized by plants

Answer 34

Vitamin K

Question 35

Vitamin K in plants

Answer 35

phylloquinone

Question 36

Vitamin K in bacterica

Answer 36

menaquinone

Question 37

is a highly hydrophobic molecule which is incorporated into cell membranes, where it functions as an antioxidant that prevents oxidative damage to membrane proteins and lipids.

Answer 37

Vitamin E

Question 38

is derived mainly from plant products such as β-carotene

Answer 38

Vitamin A or retinol

Question 39

act at very low concentrations and are involved in the production of pain and fever, and in the regulation of blood pressure, blood coagulation, and reproduction.

Answer 39

Eicosanoids

Question 40

In aqueous solutions, amphiphilic molecules such as soaps and detergents (single- tailed lipids) aggregate forming what

Answer 40

micelles

Question 41

In aqueous solutions, phospholipids (glycerophospholipids or sphingomyelins) can form liposomes which are self-sealing solvent-filled vesicles made of only a single bilayer.

Answer 41

Lipid Bilayers

Question 42

catalyze chemical reactions, mediate the flow of nutrients and wastes across the membrane, and participate in relaying information about the extracellular environment to various intracellular components.

Answer 42

Membrane proteins

Question 43

associate tightly with membranes through hydrophobic effects and can be separated from membranes only by treatment with agents that disrupt membranes.

Answer 43

Integral or intrinsic proteins

Question 44

which are channel-forming proteins in the outer membrane of gram-negative bacteria

Answer 44

porins

Question 45

permit the entry of small polar solutes such as nutrients

Answer 45

porins

Question 46

can be dissociated from membranes by relatively mild procedures that leave the membrane intact, such as exposure to high ionic strength salt solutions or pH changes

Answer 46

Peripheral or extrinsic proteins

Question 47

Lipid-linked proteins come in three varieties called what

Answer 47

prenylated proteins fatty acylated proteins glycosylphosphatidylinositol-linked proteins

Question 48

is defined by the fluid mosaic model. A key element of the model is that integral proteins can diffuse laterally in the lipid matrix

Answer 48

membrane structure

Question 49

facilitate the fusion of membranes by bringing them together

Answer 49

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