Lipid Structure + Function

Question 1

Triaglycerols contain ___ fatty acids linked to a ____

Answer 1

three fatty acids linked to a glycerol

Question 2

What are the important roles of lipids in biology

Answer 2

energy storage, cell membranes, endocrine signaling

Question 3

Glycerophospholipids and sphingolipids form _____ ____ of cell and plasma membranes

Answer 3

hydrophobic barriers

Question 4

Eicosanoids function in the _____ and acivate _____ ____

Answer 4

endocrine system, activate signaling pathways

Question 5

Animal fats contain triaglycerols with a high portion of ________ which form solids at room temp

Answer 5

long chain SATURATED fatty acids

Question 6

Vegetable oils contain triaglycerols with_____________ resulting in a low melting point

Answer 6

mixtures of saturated and unsaturated fatty acids

Question 7

What is hydrogenation

Answer 7

commercial process used to generate saturated and trans fatty acids

Question 8

What are the “bad fats”

Answer 8

me… lol jk saturated and trans fats

Question 9

what are the “better fats”

Answer 9

mono and polyunsaturated fats

Question 10

are omega-3 fatty acids good for you?

Answer 10

yis

Question 11

what can omega-3 fatty acids do for you?

Answer 11

lowers blood pressure, decrease growth rate of of atheroscleorotic plaque etc

Question 12

beeswax contains ___% long-chain saturated fatty acids

Answer 12

70

Question 13

beef fat contain triacylglycerols that contain mostly ______ long-chain fatty acids, making them _____ at room temp

Answer 13

saturated, solid

Question 14

Soap is made from ______ triacylglycerols and removes grease form clothes by forming _____

Answer 14

micelles

Question 15

T or F: triacylglycerols are the primary form of storage in animals

Answer 15

T

Question 16

What are the 6 steps in triacylglycerol digesion

Answer 16

1. emulsification by bile
2. hydrolysis by intenstinal lipases to free fatty acids
3. resynthesis in intestinal epithelial cells
4. packaging into chylomicrons
5. export to lymphatic system
6. entry to circulatory system through subclavian

Question 17

T or R: Cylormicrons are the largets of all lipoproteins

Answer 17

T

Question 18

What is the role of chylomicrons

Answer 18

transport lipids to adipose, cardiac and skeletal muscle tissue

Question 19

what are the steps in lipid transport from gut lumen to periphery to liver

Answer 19

• 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

Question 20

what are the two steps in mixed lipid composition of chylomicron

Answer 20

1. chylomicrons dock on epithelium where LpL hydrolises CM triglycerides into nonesterified fatty acid to delivier lipids
2. CM reminant lipoproteins released back into the plasma, liver rapidly and safely removes from circulation

Question 21

Fatty acids synthesized in the liver from acteyl-CoA are used to generate _________ before being packaged into _________

Answer 21

triacylglycerols, lipoproteins

Question 22

VLDL particles are one type of protein secreted from the ______

Answer 22

liver

Question 23

Glucagon signaling in apidocytes stimulates the release of ___ _____ ____

Answer 23

free fatty acids

Question 24

Free fatty acids are released by ____ _____

Answer 24

lipase cleavage

Question 25

What are the three main lipid types in cell membranes

Answer 25

phospholipids, glycolipids and sterols

Question 26

what is the structure of a sterol

Answer 26

polar, a 4 hydrocarbon ring

Question 27

where are glycolipids derived from

Answer 27

sphingosine

Question 28

what are the three major types of membrane lipids

Answer 28

glycerophopsholipids, sphingolipids and cholesterol

Question 29

Polar gorups of membrane lipids orient towards _____ and nonpolar tails orient towards ______

Answer 29

aqueous environment, hyrdophobic center

Question 30

T or F: sphingomyelin isnt considered a phospholipid

Answer 30

F

Question 31

What are the most abundant membrane lipids

Answer 31

glycerphoshpolipids

Question 32

What is the core structure of all four sphingolipids

Answer 32

all contain a sphingosine and a fatty acid

Question 33

Steroidogenesis generates cholesterol derived hormones through action of ________

Answer 33

cytochrome P450 monoxygenases

Question 34

Progesterone is synthesized in the _____ and aids in ____

Answer 34

Corpus Luteum, Menstruation

Question 35

Corisol is synthesized in the _____ and aids in ____

Answer 35

Adrenal cortex, liver metabolism and stress

Question 36

Aldosterone is synthesized in the _____ and aids in ____

Answer 36

Adrenal cortex, kidney and ion transport and blood pressure

Question 37

Testosterone is synthesized in the _____ and aids in ____

Answer 37

testes, male reproductive organs

Question 38

Estradiol is synthesized in the _____ and aids in ____

Answer 38

Ovaries, female reproductive organs

Question 39

the four major classes of eicosanoids are all derived from ________

Answer 39

polyunsaturate fatty acid arachidonate

Question 40

activation of GCPR leads to stimualation of _____ activity thorugh ____ subunits

Answer 40

phospholipase A2, G by