Lipids

Question 1

What are lipids?

Answer 1

characterized by insolubility in water and solubility in nonpolar organic solvents

Question 2

What is the structure of phospholipids?

Answer 2

a phosphate and alcohol that comprise the polar head group, joined to a hydrophobic fatty acid tail by phosphodiester linkages

Question 3

What does fully saturated mean?

Answer 3

mean the chain only has single bonds - so saturated with hydrogens

Question 4

What are glycerophospholipids?

Answer 4

phospholipids that contain a glycerol backbone bonded by ester linkages to two fatty acids and a by a phosphodiester linkage to a highly polar head group

Question 5

What are sphinoglipids?

Answer 5

have a sphingosine backbone and long-chain, nonpolar fatty acid tails and polar head group s

Question 6

What is a ceramide?

Answer 6

a sphingolipid with a single hydrogen atom as its head group

Question 7

What are sphingomyelins?

Answer 7

major class of sphingolipids that are also phospholipids; have either phosphatydylcholine or phosphatidylethanolamine as head group and contain a phosphodiester bond; not net charge on head groups

Question 8

What are glycosphingolipids?

Answer 8

sphingolipids with head group composed of sugars bonded by glycosidic linkages; not phospholipids (lack phosphodiester linkage)

Question 9

What are cerebrosides?

Answer 9

glycosphinoglipids with a single sugar

Question 10

What are globosides?

Answer 10

glycosphingolipids with two or more sugars

Question 11

What are gangliosides?

Answer 11

glycolipids that have polar head groups composed of oligosaccharides with one or more n-acetylneuraminic acid (NANA)

Question 12

What are waxes?

Answer 12

esters of long-chain fatty acids with long-chain alcohols

Question 13

What are terpenes?

Answer 13

a class of lipids built from isoprene moieties and share a common structural pattern with carbon grouped in multiples of five; mainly produced by plants and insects

Question 14

How many isoprenes are in a terpene?

Answer 14

two

Question 15

What are steriods?

Answer 15

characterized by having four cycloalkane rings fused together: three cyclohexane and one cyclopentane; nonpolar

Question 16

What are steroid hormones?

Answer 16

steroids that act as hormones; they are secreted by endocrine glands and travel on protein carriers to distant sites and bind to specific high-affinity receptors and alter gene expression levels

Question 17

What is cholesterol?

Answer 17

major component of the phospholipid bilayer and is responsible for mediating membrane fluidity; amphipathic

Question 18

What are prostaglandins?

Answer 18

20-carbon molecules are unsaturated carboxylic acid derived from arachidonic acid and contain one-five carbon ring; act as paracrine and autocrine signaling molecules

Question 19

What is the biological function of prostaglandins?

Answer 19

regulate the synthesis of cyclic adenosine monophosphate (cAMP)

Question 20

What is a vitamin?

Answer 20

essential nutrient that cannot be adequately synthesized and must be consumed; water and lipid soluble

Question 21

What is vitamin A?

Answer 21

carotene; unsaturated hydrocarbon that is important in vision, growth and development, and immune function

Question 22

What is vitamin D?

Answer 22

cholecaliciferol; consumed or formed in a UV light-driven reaction in the skin; increases calcium and phosphate uptake in the intestines, which promote bone growth

Question 23

What are rickets?

Answer 23

a condition seen in children and characterized by underdeveloped, curved long bones as well as impeded growth caused by lack of Vitamin D

Question 24

What is vitamin E?

Answer 24

tocopherols and tocotrienols; characterized by a substituted aromatic ring with a long isoprenoid side chain and are characterstically hydrophobic; antioxidants

Question 25

What is vitamin K?

Answer 25

a group of compounds, including phylloquinone and menaquinones; critical to posttranslational modifications required to form prothrombin, important clotting factor in the blood

Question 26

What is a triacylglycerol?

Answer 26

three fatty acids bonded by ester linkages to glycerol; nonpolar and hydrophobic

Question 27

What is saponification?

Answer 27

the ester hydrolysis of triacylglycerols using a strong base

Question 28

What is lye?

Answer 28

sodium or potassium hydroxide