Lipid Structure + Function Flashcards
Triaglycerols contain ___ fatty acids linked to a ____
three fatty acids linked to a glycerol
What are the important roles of lipids in biology
energy storage, cell membranes, endocrine signaling
Glycerophospholipids and sphingolipids form _____ ____ of cell and plasma membranes
hydrophobic barriers
Eicosanoids function in the _____ and acivate _____ ____
endocrine system, activate signaling pathways
Animal fats contain triaglycerols with a high portion of ________ which form solids at room temp
long chain SATURATED fatty acids
Vegetable oils contain triaglycerols with_____________ resulting in a low melting point
mixtures of saturated and unsaturated fatty acids
What is hydrogenation
commercial process used to generate saturated and trans fatty acids
What are the “bad fats”
me… lol jk saturated and trans fats
what are the “better fats”
mono and polyunsaturated fats
are omega-3 fatty acids good for you?
yis
what can omega-3 fatty acids do for you?
lowers blood pressure, decrease growth rate of of atheroscleorotic plaque etc
beeswax contains ___% long-chain saturated fatty acids
70
beef fat contain triacylglycerols that contain mostly ______ long-chain fatty acids, making them _____ at room temp
saturated, solid
Soap is made from ______ triacylglycerols and removes grease form clothes by forming _____
micelles
T or F: triacylglycerols are the primary form of storage in animals
T
What are the 6 steps in triacylglycerol digesion
- emulsification by bile
- hydrolysis by intenstinal lipases to free fatty acids
- resynthesis in intestinal epithelial cells
- packaging into chylomicrons
- export to lymphatic system
- entry to circulatory system through subclavian
T or R: Cylormicrons are the largets of all lipoproteins
T
What is the role of chylomicrons
transport lipids to adipose, cardiac and skeletal muscle tissue
what are the steps in lipid transport from gut lumen to periphery to liver
- detergents in hepatic bile emulsify lipids from food to form micelles
- panreas secretes lipases that digest dietary lipids into chemical form
- absorption of fatty acids and monoacylglycerides approaches 100% efficiency
- Cholesterol absorption 50% efficient, eterocytes reesterify lipids
- particles secreted into throactic lymph which drains into bloodstream
what are the two steps in mixed lipid composition of chylomicron
- chylomicrons dock on epithelium where LpL hydrolises CM triglycerides into nonesterified fatty acid to delivier lipids
- CM reminant lipoproteins released back into the plasma, liver rapidly and safely removes from circulation
Fatty acids synthesized in the liver from acteyl-CoA are used to generate _________ before being packaged into _________
triacylglycerols, lipoproteins
VLDL particles are one type of protein secreted from the ______
liver
Glucagon signaling in apidocytes stimulates the release of ___ _____ ____
free fatty acids
Free fatty acids are released by ____ _____
lipase cleavage
What are the three main lipid types in cell membranes
phospholipids, glycolipids and sterols
what is the structure of a sterol
polar, a 4 hydrocarbon ring
where are glycolipids derived from
sphingosine
what are the three major types of membrane lipids
glycerophopsholipids, sphingolipids and cholesterol
Polar gorups of membrane lipids orient towards _____ and nonpolar tails orient towards ______
aqueous environment, hyrdophobic center
T or F: sphingomyelin isnt considered a phospholipid
F
What are the most abundant membrane lipids
glycerphoshpolipids
What is the core structure of all four sphingolipids
all contain a sphingosine and a fatty acid
Steroidogenesis generates cholesterol derived hormones through action of ________
cytochrome P450 monoxygenases
Progesterone is synthesized in the _____ and aids in ____
Corpus Luteum, Menstruation
Corisol is synthesized in the _____ and aids in ____
Adrenal cortex, liver metabolism and stress
Aldosterone is synthesized in the _____ and aids in ____
Adrenal cortex, kidney and ion transport and blood pressure
Testosterone is synthesized in the _____ and aids in ____
testes, male reproductive organs
Estradiol is synthesized in the _____ and aids in ____
Ovaries, female reproductive organs
the four major classes of eicosanoids are all derived from ________
polyunsaturate fatty acid arachidonate
activation of GCPR leads to stimualation of _____ activity thorugh ____ subunits
phospholipase A2, G by
