Exam 3: Lipids Flashcards
What are lipids made of
C, H and O
What are the classes of lipids
fatty acids, triaglycerols/ triglycerides, eicosanoids, isoprenoids, lipoproteins
What are the 3 kinds of lipoproteins
LDL, HDL, VLDL
Are lipids mostly hydrophobic or hydrophillic?
hydrophobic
What is the basic structure of fatty acids
carboxyl group + HC tail
What is the name of the last C in the fatty acid chain
omega C
Explain the main difference between saturated and non saturated fatty acids
non: no double bonds
saturated: has 1+ double bonds
Are most fatty acids cis or trans
cis
what are the physical properties of saturated and unsaturated fatty acids
sat: solid at room temp
un: liquid at room temp
What are trans fatty acids?
have trans double bond conformation
What portion of a fatty acid is hydrophobic?
HC chain
What do eicosanoids do
autocrine, local signaling
What is the precursor for all ecosenoids
arachidonic acid
What are the families of eicosanoids
prostaglandin E2, thromboxanes, leukotrienes
What do prostaglandins do
signal inflammation and pain
What inhibits prostraglandins
NSAIDS, non steroidal anti inflammatory drugs
ibuprofen, aspirin, naproxen
What enzyme catalyzes reaction between arachidonic acid and prostaglandin
cyclo oxygenase
What is the difference between Cox-1 and cox-2 NSAIDS
cox 1: protects mucus, constitutive
cox 2: inducible, mediates pain, inflammation and fever.
What does thromboxane do
platelet aggregation after tissue injury
What does leukotriene C4 do
attracts immune cells, broncho constriction, allergy response
What are triacylgylcerols what do they do
esters of glycerol, used for energy storage also can act as water repellent
What are phospholipids or phosphoglycerides
have a P group at C3, amphipathic, membranes
What is the structure of a phospholipid
glycerol with 2 fatty acids attached
What do phospholipases do
change the composition of membrane, hydrolyze ester bonds can cleave fatty acids at X group
What are isoprenoids made of
repeating isoprene units
What are the 2 subclasses of isoprenoids
terpenes:
Steroids:
What is an example of a terpene
vitamin K, present in plants, eat your vegetables kids
What are steroids from
squalene converted into ring
What is the most abundant lipid in organisms
cholesterol
What part of cholesterol is hydrophobic? polar?
OH-polar
hydrophobic-bulky part
What are lipoproteins
lipids + proteins that can transport hydrophobic lipids around body
What are the 4 classes of lipoproteins
LDL: bad, mostly cholesterol
HDL: good, mostly proteins
VLDL: mostly made of triaglycerol
chylomicrons: dietary, mostly made of triacyglycerols and proteins
Describe the structure of lipoproteins
ball of of cholesterol and phospholipids on outside, inside made of cholesterol esters, tubes of apolipoproteins
What is the function of LDLs
transports cholesterol and cholesterol esters to tissues
What is the function of HDLs
collects excess cholesterol from cell membranes or from LDL to liver
What is the function of VLDL
transport lipids from liver to tissues
In the fluid mosaic model of membrane structure
proteins float in a lipid bilayer
