Ch. 5 Lipids- NOT high yield

lipids are insoluble in ____ and soluble in _____ ____ ______

water, nonpolar organic solvents

_______ are amphipathic and form the bilayer of biological membranes

phospholipids

phospholipids contain a hydrophilic (polar) ____ group and a hydrophobic (nonpolar) _____

head, tail

the head group is attached by a ___ ____ and because it interacts with he environment, determines the

phosphodiester linkage, function of the phospholipid

the ____ of the fatty acid tails determines the fluidity of the membrane

saturation

are saturated fatty acids more or less fluid than unsaturated ones

less

glycerophospholipids

phospholipids that contain a glycerol backbone

sphingolipids

contain a sphingosine or sphingoid backbone

sphingophospholipids

phospholipids containing a phosphodiester bond

sphingomyelins are the

major class of sphingophospholipids and contian a phosphatidylcholine or phosphatidylethanolamine head

sphingomyelins are a major component of the

myelin sheath

glycosphingolipids are attached to what instead of a phosphate group

sugar moieties

____ have one sugar connected to sphingosine, while ____ have two or more

cerebrosides, globosides

_____ contain oligosaccharides with at least one terminal N-acetylneuraminic acid (NANA; also called sialic acid)

gangliosides

_____ contain long-chain fatty acids esterified to long chain alcohols

waxes

waxes are used as

protection against evaporation and parasites in plants and animals

terpenes

odiferous steroid precursors made from isoprene (a 5 carbon molecule)

one terpene unit (a monoterpene) contains ___ isoprene units

2

how can carbons does a terpene have

10

(one isoprene = 5, terpene = 2 isoprene, 5×2 = 10)

terpenoids are derived from terpenes via

oxygenation or backbone rearrangement

steroids contain 3 ____ rings and 1 _____ ring

cyclohexane, cyclopentane

_____ hormones have high-affinity receptors, work at low concentration, and affect gene expression and metabolism

steroid

____ is a steroid important to membrane fluidity and stability; it serves as a precursor to lots of other molecules

cholesterol

prostaglandins are autocrine and paracrine signaling molecules that regulate ___ levels

cAMP

prostaglandins have powerful effects on

1. smooth muscle contraction

2. body temp

3. sleep-wake cycle

4. fever

5. pain

the fat-soluble vitamins are

• D

• E

• A

• K

Vitamin A (carotene) is metabolized to _____ for vision and ___ ___ for gene expression in epithelial development

retinal, retinoic acid

Vitamin D (cholecalciferol) is metabolized to ___ in the kidneys

calcitriol

what does calcitriol do

regulates calcium and phosphorus homeostasis in the intestines (increasing calcium and phosphate absorption) promoting bone formation

a deficiency in vitamin D causes

rickets

vitamin E (tocopherols) act as ___ ____, their aromatic rings destroy free radicals, preventing oxidative damage

biological antioxidants

vitamin K (phylloquinone and menaquinones) is important for

formation of prothrombin, a clotting factor

Vitamin K also performs

postranslational modifications on several proteins, creating Ca2+ binding sites

triacylglycerols (triglycerides) are the preferred method of

storing energy for long term use

triacylglycerols contain one glycerol attached to three fatty acids by ___ bonds

ester

the carbon atoms in lipids are more reduced than carbohydrates, giving twice as much ____ per gram during oxidation

energy

triacylglycerols are very hydrophobic, so they are not

hydrated by body water and do not carry additional water weight

animal cells specifically used for storage of large triacylglycerol deposits are called

adipocytes

free fatty acids are

unesterified fatty acids that travel in the blood stream

salts of free fatty acids are soaps and can be synthesized in

saponification

saponification is the

ester hydrolysis of triacylglycerols using a strong base, like sodium or potassium hydroxide

soaps act as surfactants, forming

micelles

a micelle can

dissolve a lipid-soluble molecule in its fatty core, and washes away with water because of its shell of carboxylate head groups