animal nutrition lab - lipids

lipid energy storage

2.25x amount of carbohydrates

lipid functions

energy storage, carry fat-soluble vitamins, found in cell membranes, waxes

lipids in cell membranes

important roles in cell-signaling. glycerophospholipids, phospholipids, and sterol lipids form key components of the biological membrane

waxes

esters of fatty acids are found in leaves, fruits, feathers of birds, and fur of animals providing protection from dehydration

lipids are components of:

plant and animal tissue.

lipid solubility

insoluble in water. soluble in organic solvents, such as ethyl ether, benzene, or hexane

2 phases of lipids

organic & aqueous

saturated fatty acids

each carbon in the chain is fully saturated with hydrogen bonds. animal sources (lard, butter, other dairy products). typically solid at room temperature

unsaturated fatty acids

double bonds between adjacent carbons. chain is not fully saturated with hydrogen. plant sources (vegetable oil, cottonseed oil, etc). typically liquid at room temperature

essential fatty acids

required because the animal cannot synthesize them in high enough amounts or at all. fat soluble vitamins. required for biological processes but does not include the fats that only act as fuel. 

fat soluble vitamins

A, D, E, K

mammal essential fatty acids

linoleic acid, linolenic acid, and occasionally arachadonic acid. if fed in excess, these EFAs will contribute to energy

linoleic acid

C18:2 (Omega 6)

linolenic acid

C18:3 (Omega 3)

arachadonic acid

C20:4. can be synthesized from lenoleic acid if not supplied

bile aids in digestion of lipids through _______

emulsification

ingesta enters the duodenum=hormonal response to release:

bile

emulsification

process in which large lipid globules are broken down into several small lipid globules. small globules can then be distributed throughout the chyme (ingesta)

micelles

tiny spheres formed by bile salts surrounding long-chain fatty acids and monoglycerides

lipases can only act efficiently on the lipids when they are broken into _____ droplets.

small

lipases break down lipids into:

fatty acids and glycerides

micelle heads

hydrophillic (water loving)

micelle tails

hydrophobic (water-hating)

micelles in digestion

brush border of small intestine

long chain fatty acids and monoglycerides diffuse out of the micelles and into the_____

enterocyte

triglycerides=

long chain fatty acids + monoglycerides

triglycerides + proteins

chylomicrons

chylomicrons inside

triglycerides, cholesterol, and other lipids

chylomicrons surface

proteins, hydrophillic phosphate “heads” of phospholipids. enable the chylomicron to move in an aqueous environment without exposing the lipids to water