9.1

Question 1

Membrane fluidity

Answer 1

• kinks = more fluid, more disruptions
• DECREASED length = more fluid
• cholesterol = maintains fluidity at low temperatures and decreases fluidity

Question 2

micelle

Answer 2

SOLVATION SHELL

Question 3

what is the technical name for FAT?

Answer 3

triacylglycerol/triglyceride

Question 4

what is saponification

Answer 4

release of fatty acids from glycerol

Question 5

why are fats better storage molecules?

Answer 5

1. HYDROPHOBICITY (close packing); sugars love water

2. More REDUCED

Question 6

van der waals

Answer 6

MORE in SATURATED fatty acids = LESS FLUID

Question 7

how do steroids act?

Answer 7

they diffuse through lipid bilayer

Question 8

terpenes are made of

Answer 8

5 Cs, 8 Hydrogens (=ISOPRENE)

a terpene is TWO isoprenes

Question 9

name several terpenes

Answer 9

1. limonene (monoterpene = 2 isoprenes)
2. humulene (sesquiterpene = 3)
3. taxadiene (diterpene = 4)
4. squalene (triterpene = 6) -> important for steroids (“the squalid three”)

functionalized terpenes (addition of other elements) = TERPENOIDS (VITAMIN A)

Question 10

steroid cholesterol

Answer 10

obtain from DIET, synthesized in LIVER

packaged with FATS and PROTEINS into lipoproteins (artery plaques)

“Oh Estrogen!”

Question 11

draw Sphingolipid (sphingomyelin) / Wax

Answer 11

wax has ESTER linkage

Sphingo = goal posts (OH - C - C - C - OH)

Question 12

fat soluble vitamins

Answer 12

A-Dek (ADEK)

All are RINGED structures

A is a TERPENOID

D is from CHOLESTEROL - regulates blood levels of calcium and phosphate (“D is 4th letter, four rings”)

E is TOCOPHEROL - mEEEthylated phenol - important as ANTI-OXIDANT (alpha-tocophenol)

K - activates clotting proteins (“KKloting”)

Question 13

Prostaglandins (draw A, E1, E3alpha)

Answer 13

p. 173

EICOSANOIDS (eicosa means 20)

derived from 20-carbon fatty acids (20)

regulate smooth muscle contraction in intestines, uterus, blood vessel diameter, gastric integrity

5-CARBON RING! “Pro5taglandins”

Question 14

chylomicrons preceding FA oxidation

Answer 14

composed of FAT and LIPOPROTEIN, transported in lymphatic and blood stream

dump triacylglycerol, is HYDROLYZED to liberate FREE FATTY ACIDS which undergo BETA-OXIDATION at OUTER MITOCHONDRIAL MEMBRANE (ACTIVATION of fatty acid)

catalyzed by acyl-CoA synthetase, requires two ATP equivalents to generate a fatty acyl-CoA which is transported into the mitochondria

FA oxidation occurs in the MITOCHONDRION

Question 15

Fatty acid BETA oxidation

Answer 15

ACTIVATION: first acyl-CoA synthetase requires two ATP to greate fatty acyl-CoA, which goes to the mitochondrion

produces acetyl-CoA (sent to Krebs cycle)

lauric acid (12 carbons)

requires FAD and NAD+

• 2 ATP investment activation
• 5 rounds of beta oxidation
• 5 FADH2
• 5 NADH
• 6 Acetyl-CoA (18 NADH, 6 FADH, 6 GTP)

11 FADH = 16.5 ATP
23 NADH = 46 + 11.5 = 57.5 ATP
6 ATP
= 80 ATP - 2 ATP = 78 ATP

Question 16

ketogenesis

Answer 16

production of KETONE BODIES in the LIVER

generated from acetyl-CoA

include ACETONE, ACETOACETATE, BETA-HYDROXYBUTYRATE -> crosses BBB -> converted back to acetyl-CoA once they arrive to target organ

Acetyl-CoA -> Ketone body -> acetyl-CoA

occurs when glucose cannot enter the cell

Question 17

Q: Acetyl-CoA is a allosteric inhibitor of PFK

Answer 17

na

Question 18

bile is made from

Answer 18

cholesterol

Question 19

what three biochemical pathways occur in cytoplasm and mitochondria?

Answer 19

1. gluconeogenesis (GNG)
2. heme synthesis
3. urea cycle

GNG begins in the matrix, finishes in the cytosol

Question 20

fatty acid synthesis occurs in the…

Answer 20

cytoplasm

FAS

Question 21

Acetyl-CoA cannot be converted to glucose

Answer 21

see map

Question 22

Fatty acid activation

Answer 22

fatty acid -> acyl-CoA (the activated fatty acid is BETA OXIDIZED)

fatty acid -> acyl adenylate (AMP) -> acyl CoA

Question 23

what is the carbon skeleton of AA also called?

Answer 23

alpha-keto acid!

Question 24

Fatty acid synthesis

Answer 24

1. addition of 2-carbon subunits
2. carboxylation of acetyl-CoA (start with acetyl-CoA) to form malonyl-CoA (3 carbon); this requires ATP

• CO2 is lost
• NADPH is consumed (reduces the carbonyl groups)

FAS - multiple catalytic domains (ACP acyl carrier protein), CYS residue