Lecture 1 Flashcards
Lipids dissolve in what?
Organic Solvents
Name 3 organic solvents that lipids dissolve in
Cholorform, Ether, Acetone
6 places you can find lipids
Energy sources from diet
Cell and organelle membrane constituent
Constituents of fat-soluble vitamins, hormones, Co-Q, and mediators of eTC
What is Coenzyme Q
An enzyme used in oxidative phosphorylation process in mitochondria that turns carbs and fats into ATP (to be used for synthesis)
3 simple lipids
Triacylglycerols, diacylglycerol, monoglycerol
Fatty Acids
Waxes
2 types of waxes
Sterol Esters (Cholesterol fatty acid ester) Non sterol esters (Vitamin A ester)
7 types of compound lipids
Phospholipids phosphatidic acids (cell signaling) plasmalogens (cell signal) sphingomyelins (cell signal) Glycolipids Lipoproteins Derived Lipids
What does a phospholipid do?
Forms a permeable barrier to cell membrane
What do glycolipids do?
Stabilize cell membrane and facilitate cell to cell interaction
Job of lipoproteins
Transport simple lipids
What is a derived lipid
Sterols/straight chain alcohols from simple/compound lipid hydrolysis that still have lipid properties such as ethyl alcohol
How long can a carbon chain length be in a fatty acid?
Between 4-24 carbon atoms having a hydrophobic and hydrophilic end
Which type of lipid provide most of dietary energy from fat
Fatty Acid
At what pH does the carboxyl terminal group of FA ionize?
4.8 making it lose the H and forming a negative charge making it amphipathic
COOH -> COO-
In LCFA which portion is the largest?
The hydrophobic portion making it insoluble
Over __% of FA in plasma are in the form of _____.
Name the 3 types
90
esters
TAG
Cholesterol
Phospholipids
What is a saturated lipid?
Single bonded carbon-carbon
What is a MUFA
1 double bond
What is a PUFA
2 or more double bonds
The prescence of C=C allow for what?
cis and trans conformation
What allows for cis and trans conformation on lipid?
C=C
Do trans assume a straight or twisting shape?
Straight
Do Cis assume a straight or twisting shape?
Twisting into U-Like shape
What is the significans of twisting role of FA?
Structure and function of cell membrane
Most FA’s in nature are in what form?
Cis
How are Trans fats made (2 ways)?
by ruminant digestive processes (hence presence in beef and dairy products)
By hydrogenation
Cis double bonds that are not reduced to single bond by the heat rearrange to what?
Trans
Delta system counts double bonds from which end?
Carboxyl Group
Omega system counts double bonds from which end?
Methyl
Omega 3 is which type of acid
Linolenic
Omega 6 is which type of acid?
Linoleic
DIfference between omega and Delta system
20:4 ω-6
Omega tells us where first double bond is
18:2(Δ9,12)
Delta tells us where every double bond is
How many carbons separate a FA
3
What is the precursor for arachidonic?
Linoleic acid (provide energy)
Precursor to linolenic acid in vivo?
Linoleic acid
Linoleic makes what?
yLinolenic->Eiconsatrienoic->Arachidonic(needed to make prostaglandins and leukotrienes which aid in immune function)
What does desaturation mean?
Add a cis or trans double bond
What does saturation mean?
Removing a double bond
What is responsible for desaturation?
Mixed function oxidase enzyme
What occurs in mixed function oxidase enzyme
What two components make this possible?
Desaturation (adding a double bond) by using NADPH and oxygen
Mixed function oxidase enzymes add double bonds using NADPH and Oxygen for what?
make Polyunsaturated FAtty Acids
Humans lack the enzyme to insert double bonds between which carbons?
Delta 12 and 15 (delta 12 and delta 15 desaturases is needed which are found in plants which is why we consume foods with omega 3 and 6)
FA are esterified through which group?
Carboxyl group resulting in the loss of negative charge and forming a neutral fat
FA are esterified through their carboxyl group resulting in the loss of what?
Their negative charge, forming a neutral fat
COO- -> COOR
Glycerol has 3 molecules where carbon 1 is ____ carbon 2 is _____ and carbon 3 is _____
saturated
unsaturated
either
Does UFA lower or raise melting temp?
Lowers
What does esterified mean?
To form an ester (H on carboxyl end of OH is replaced by alkyl group) COOH -> COOR
Double bonds prefer which configuration?
Cis causing a bend at double bond site
Cis double bonds cause a what?
Bend at double bond site
Does increasing length of carbon chain increase or decrease melting temperature?
Increase
What makes cell membranes flexible?
LCFA double bonds
Adding FA to glycerol is done by what?
esterification
What enzyme removes a FA from glycerol?
Lipase
FFA are transported by what?
albumin
What happens when FFA attach to albumin?
Transported to various tissues for oxidation
Another name for a 4 ring core structure/ steroid nucleus?
Cyclo
Pentano
Perhydro
Phenanthrene
Sterols are what?
Monohydroxyl alcohols
Most common sterol?
Cholesterol
Cholesterol is primary substrate for synthesis of what?
steroids
Cholesterol can be found in what two forms?
Free or esterified
Do human enzymes recognize plant sterols?
No
80% of cholesterol in humans is made by what?
Liver
What percentage of cholesterol in humans is made by liver?
80%
5 products made from cholesterol
Steroids Sex hormones Bile acids Adrenal hormones Vitamin D
3 ways you can determine difference of sterol
POsition of double bonds on the ring system
Presence of carbonyl or hydroxyl groups
Type of side chain on carbon 17
What converts cholesterol hormones?
Desmolase
How does desmolase convert cholesterol?
It first hydroxylates carbon 20 and 22; then cleaving side chain on steroid nucleus
3 type of phospholipids?
Glycerophophatides
Sphingophosphatides
Phosphatidic acids
Example of glycerophosphatide?
Cardiolipin (needed for energy conversion in mitochondria)