Flashcards in emerald glass Deck (43):
when lipids leave the stomach, what stages of digestion have been accomplished?
physical digestion, reducing particle size
what enzymes are added when lipids leave stomach?
pancreatic lipase, co-lipase, bile, and one I forgot
what is the enzyme added when lipids just leave stomach besides pancreatic lipase, colipase, and bile?
true/false: all lipids enter circulation through lymphatic system?
false. small free fatty acids enter the circulation directly
describe the structure of a micelle
hydrophobic ends toward center and charged ends oriented toward aq. environment. they collect lipids within their hydrophobic centers
what conditions promote lipid mobilization from fat stores?
postabsorptive and fasting states
what hormones promote lipid mobilization
decrease in insulin and increase in epinephrine and cortisol will increase lipid mobilization from adipocytes
what is the ratio of free FA to glycerol produced through lipid mobilization
primary method of transporting free FA in blood
bonded to albumin and other carrier proteins. much smaller amount will remain unbonded.
order the lipoproteins from greatest percentage protein to least percentage protein. circle those primarily involved in triacylglycerol transport
HDL>LDL>IDL>VLDL>chylomicrons. The two least dense are primary triacylglycerol transporters. The two most dense are mostly involved in cholesterol transports.
lipoproteins are synthesized primarily by which two organs?
liver and intestine
where did you mess up the order in the lipoproteins?
it goes HDL>LDL>IDL, not HDL>IDL>LDL
under what conditions is HMG-CoA reductase most active
in absence of cholesterol and when stimulated by insulin
in what cellular region does HMG-CoA reductase exist
what proteins are specific to the formation and transmission of cholesteryl esters?
LCAT and CETP
What is the function of LCAT
catalyzes esterification of cholesterol to form cholesteryl esters
what is the function of CETP
promotes transfer of cholesteryl esters from HDL to IDL, form LDL
what kind of reaction does LCAT catalyze
what is the substrate of LCAT
what is the product of the LCAT reaction
what does CETP promote the transfer of
CETP promotes the transfer of a FG from what to what
HDL to IDL, forming LDL
draw palmitic acid
draw 18:3 (all-cis-9,12,15)
draw an omega-6 FA
last double bond is 6 away from end
what is the first step in the addition of acetyl-CoA to a growing FA chain?
attachment of acetyl-CoA to acyl carrier protein (so that two can be joined)
what is the second step in the addition of acetyl-CoA to a growing FA chain?
bond formation between molecules
what is the third step in the addition of acetyl-CoA to a growing FA chain?
reduction of a carboxyl group
what is the fourth step in the addition of acetyl-CoA to a growing FA chain?
what is the fifth step in the addition of acetyl-CoA to a growing FA chain?
reduction of a double bond
how is beta-ox of unsat different from that of sat FA?
for unsat, you gotta change stereochem. you need an additional isomerase and an additional reductase
T/F: FA are synthesized in cytoplasm and modified by enzymes in smooth ER?
why are FA used to create ketone bodies instead of creating glucose?
FA degradation results in large amounts of acetyl-CoA, which cannot freely enter the gluconeogenic pathway. only odd-numbered FA can provide the final malonyl-CoA for gluconeo
what conditions favor ketogenesis
prolonged fasting and increased conc of acetyl-CoA
where does ketogenesis occur
what conditions favor ketolysis
prolonged fasting, like ketogenesis. low energy state in brain and muscle.
what tissues favor ketolysis
brain and muscle. not liver.
T/F: bodily proteins will commonly be broken down to provide acetyl-CoA for lipid synthesis
false. proteins are more valuable to cell than lipids, thus they will not commonly be broken down for lipid synthesis
where does the bulk of protein digestion occur?
what is the fate of the carbon skeleton during protein processing?
transport to liver for processing into glucose or ketone bodies
what is the fate of the amino group during protein processing?
feed into urea cycle for excretion
what is the fate of the side chains during protein processing?
basic side chains are treated like amino group, others are treated like carbon skeleton (tsport to liver for processing into glucose or ketone bodies)