Chapter 5: Lipid Structure and Function

Phospholipids

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

Saturated fatty acid

Only have single bonds

Unsaturated fatty acid

One or more double bond

Sphingolipids

Contain a spingosine or sphigoid backbone

Spingomyelin

major class fo phingophospholipids and contain phosphatidylethalimine head group. Major component fo myelin sheath

Glycosphingolipids

Attached to sugar moicties instead of phosphate group

Cerebrosides

One sugar connected to sphingosine

Globoside

Two or more

Ganglioside

Contain oligosaccharide with at least one terminal NANA

Waxes

contain long chain fatty acids esterfied to long chain alcohols.

Wax purposes

Used as prote tion against evaporation and parasite in plants and animals

Terpenes

Class of lipids built from isoprene and share common structural pattern with C grouped in multiples of five

Monoterpene

One terpene unit, containing two isoprene units

Terpenoids

Derived from terpenes via oxygenation or backbone rearrangement

Steroids

Metabolic derivatievs of terpenes, characterized by four cycloalkane rings fused together, three cyclohexane and one cyclopentane

Steroid hormone

Steroid that act as hormones

Chloesterol

Major component of the phospholipid bilayer and responsible mediating membrane fluidity

Prostaglandin

20 carbon molecules, unsaturated carboxylic acids dervied from arachidonic acid and contain one five carbon ring

Functions of prostaglandin

Paracrine/autocrine signaling molecule, regulate cAMP levels and power effects on smooth muscle contraction, body temp, sleep wake cycle, fever, pain

Vitamin

Essential nutrient that cannot be adequately synthesized by body and therefore must be consumed in diet

Vitamin A (carotene)

unsaturated hydrocarbon important for vision growth development and immune function

Vitamin D

can be consumed or formed in UV light driven reaction in skin. increase Ca adn phosphate uptake in intestine leading increase bone production

Vitamin E (tocopherol, Tocothenols)

Aromatic ring with long isoprenoid side chain hydrophobic biological antioxidant

Vitamkin K

Post translational modification required prothrombin Ca+ binding sites on proteins

Triacyglycerols

Class lipids specifically used energy storage, three fatty acid bonded by ester linkages to glycerol

Adipocyte

Special cell in animal store large amount of fat and found under skin, mammary gland and in abdominal cavity

Free fatty acid

Unesterfied fatty acids with a free carboxylate group

Saponification

ester hydrolysis of triacylglycerol using a strong base

Surfacant

Lower surface tension at surface of liquid

Micelle

Tiny aggregate of soap with hydrophobic tails turned inward and hydrophillic heads turned outward, shielding the hydrophobic lipid tails and allowing overall solvation