Biochemistry Exam #4

Front 1

fatty acids

Back 1

these lipids include neutral fat, triacylglycerol

Front 2

isoprenoid

Back 2

multiple ring organic molecules

Front 3

functions of lipids

Back 3

1). energy source and storage
2). membrane structural components
3). digestive aids
4). cofactors and signaling molecules (ADEK)
5). Protection and insulation

Front 4

nomenclature and fundamental properties of fatty acids

Back 4

1). 1st carboxyl group is numbered first, then its the alpha, then its the beta
2). Carbon 3 is beta
3). Last carbon is the omega

Front 5

Saturated versus unsaturated fatty acids

Back 5

1). Stearic acid, is a saturated fatty acids
2). Unsaturated, with double bonds
3). Nomenclature: # of carbons: # of double bonds

Front 6

palmitic acid

Back 6

16:0, hexadecanoic

Front 7

linoleic acid

Back 7

18:2 (9,12), octadecadienoic

Front 8

alpha lineolic acid

Back 8

18: 3 (9,12,15), octadecatrienoic

Front 9

arachidonic acid

Back 9

20:4, eciosatetraenoic

Front 10

fatty acid properties

Back 10

soaps and solubility: pKa of most fatty acids is around 4.5

medium chain fatty acids (6 to 12 carbons)
long chain fatty acids (14 carbons or longer)

amphipathic (hydrophillic)
hydrophobic (the alkyl chain)
soaps

Front 11

fatty acid melting points

Back 11

fatty acids are held together by Van der Waals interactions,

unsaturation: increase in flexibility, most unsaturation is cis double bonds

cis double bonds prevents double packing

Front 12

ingestion of PUFA's

Back 12

PUFA's is correlated with a lower cholesterol level,

Front 13

TAG

Back 13

TAG is major form of storage lipid, constitutes bulk of dietary lipid

Front 14

compositions of glycerols in body

Back 14

mono, di, and tri-acylglycerol,
position of 1, 3 of glycerol are symmetric

Front 15

TAG's as fuel storage

Back 15

one of the advantages is that these molecules are hydrophobic and exclude water

Front 16

digestion of dietary lipids

Back 16

dietary fat, goes to the intestinal lumen for emulsification and digestion, intestine: absorption, resynthesis, packaging, blood: transport
adipose cells: storage

Front 17

emulsification

Back 17

fat droplets are available for hydrolysis, solubilized by emuslification, bile salts, increases surface area for lipolysis

Front 18

lipolysis

Back 18

hydrolytic cleavage of TAG's, lipolysis is catalyzed by pancreatic lipase, catalyzes hydrolysis of the 1, and 3 position esters of TAG's, to produce two FA's and 2 monoacyl glycerol

Front 19

water soluble intermediates

Back 19

water soluble chains are glycerol, short chain, or medium chain fatty acids

Front 20

low solubility intermediates

Back 20

2-monoacylglycerol and long chain fatty acids enter mucosal cells by free diffusions, the concentrations of these free lumenal species is very limited though.

Front 21

micelle formation

Back 21

amphipathic, coat hydrophobic, vesicles, favor bilayer formation

Front 22

critical micelle concentration

Back 22

micelles only form when the concentration of amphipathic lipids hit a certain level

Front 23

defects in digestion and absorption of dietary lipids

Back 23

excessive lipid in the stool is called steatorrhea

Front 24

causes of steatorrhea

Back 24

bile duct obstruction
pancreatic disease
celiac disease

Front 25

fatty acyl coA synthase

Back 25

TAG's in the intestinal mucosal cell involves the cytoplasmic activation of fatty acid to form a fatty acyl coenzyme A. coupled by inorganic pyrophosphatase

Front 26

intestinal triacylglycerol synthesis

Back 26

triacylglycerol synthase,

Front 27

2-MAG + 2-acyl coA

Back 27

acyltransferase to make TAG's

Front 28

fatty acids are transported through the blood by

Back 28

serum albumin, FA's can bind to it

Front 29

lipoprotein properties and functions

Back 29

serum transport of most lipids is performed by lipid/protein complexes called lipoprotein,

Front 30

chylomicrons

Back 30

chlyomicrons are large lipoproteins whose major function is to transport dietary lipids

Front 31

cholesterol acyltransferase

Back 31

cholesterol is derivaterized into an ester by ACAT.

Front 32

APO-b-48

Back 32

distinguishes chylomicrons from all other proteins

Front 33

nascent chylomicrons

Back 33

enter lymphatic drainage via lacteals

Front 34

release of chylomicrons

Back 34

change reapidly, several other apoproteins (mostly with HDL), positively transferred through them, apoproteins CII and E

Front 35

apoCII

Back 35

activates lipoprotein lipase, surface of blood vessels but primarily in adipose tissue

Front 36

apo E with apo-48

Back 36

takes chylomicron remnants binds to a receptor on the surface of liver cells called LDL receptor related protein, takes endocytosis and get fuses with lysosomes

Front 37

apoCII

Back 37

lipoprotein lipase

Front 38

hydrolysis of cholesterol ester to cholesterol or fatty acid

Back 38

cholesterol esterase

Front 39

VLDL

Back 39

glucose that is not immediately needed for energy is efficiently converted by hepatocytes to FA, to make into TAG's and into a hydrophobic pocket, TAG>>CE

Front 40

apo-B-100

Back 40

lipoprotein binds to characteristic lipoprotein, to make VLDL

Front 41

VLDL

Back 41

functions as a transporting fuel

Front 42

IDL

Back 42

Apo E with B-100 can facilitate binding to LDL receptor
IDL can be acted upon a lipase on the surface of liver cells, called hepatic triacylglycerol, lipase

TAG=CE