A. Fatty Acids
1. Found in the body as
a. ______ acids
b._______ in more complex molecules (_____)
2. Occurs in all tissues at low levels
3. Can be found in the plasma in substantial amounts during
i. _______
ii. _____
a. Free fatty acids
b. Fatty acyl esters in more complex molecules (TAG)
i. Fasting
ii. Starvation
a. Plasma Free Fatty Acids
- transported by _____
- originate from _____ of adipose tissues or circulating _____
- can be oxidized by most tissues to provide _____
- transported by serum albumin
- originate from TAG of adipose tissues or circulating lipoproteins
- can be oxidized by most tissues to provide energy
Fatty Acids are Precursors of Many Compounds like: (5)
Fatty Acids are Precursors of Many Compounds like:
a. Glycolipids
b. Phospholipids
c. Sphingolipids
d. Prostaglandins
e. Cholesteryl esters
fatty acids are…
5. Esterified Fatty Acids
- in the form of _____
- energy reserves
6. Also Attached to Certain ________ Proteins
-> enhanced ability of the proteins to associate with membranes
FATTY ACIDS
A. Structure
1. Consists of
- ___________
- terminal ___________
2. Physiologic pH
-> terminal carboxyl group (-COOH) of pKa of __-> so it ionizes, producing a ->-COO-(__) (__ group) -> (__) affinity for water -> this is responsible for ______ nature of fatty acids at physiologic pH
- hydrocarbon chain
- terminal carboxyl group
-> terminal carboxyl group (-COOH) of pKa of 4.8 -> so it ionizes, producing a ->-COO-(carboxyl) (anionic group) -> (higher) affinity for water -> this is responsible for amphipathic nature of fatty acids at physiologic pH
in the Structure of FATTY ACIDS,
3. Long Chain Fatty Acids
- _________ portion is predominant → highly water-_______→ transported in the plasma in
association with plasma proteins (_________)
4. >90% of Fatty Acids Found in the Plasma
- contained in circulating lipoprotein particles in the form of
a. _________(primarily)
b. _________
c. _________
- hydrophobic portion is predominant → highly water-insoluble → transported in the plasma in
association with plasma proteins (albumin)
a. TAG (primarily)
b. Cholesteryl esters
c. Phospholipids
B. Nature and Nomenclature of fatty acid
- 1 carboxyl group at the _____ of the chain
- _______is designated as carbon 1
- the carbon to which the carboxyl group is attached (carbon 2) is also called _____-carbon
- carbon 3 is _____-carbon
- carbon 4 is the _____-carbon
- saturated or unsaturated
- 1 carboxyl group at the end of the chain
- terminal carboxyl carbon is designated as carbon 1
- the carbon to which the carboxyl group is attached (carbon 2) is also called alpha-carbon
- carbon 3 is beta-carbon
- carbon 4 is the gamma(y)-carbon
1._______ Fatty Acids
- no double bonds in the chain
a. Nomenclature (Systematic Name)
- number of carbons
- suffix -anoic
- ex: palmitic acid (16 carbons) → hexadecanoic acid
b. Structure (General Formula)
_____________
n = specifies the number of methylene groups between methyl and carboxyl carbons
1. Saturated Fatty Acids
CH3 - (CH2)n - COOH
2. Unsaturated Fatty Acids
- have 1 or more double bonds
a. Nomenclature (3)
i.
ii.
iii.
i. Delta Numbering System
ii. Systematic Name
iii. Omega (ω) Numbering System
2. _______ Fatty Acids
a. Nomenclature
i. _______ Numbering System
- _________ carbon is designated as carbon 1
- double bond is given the number of the carbon atom on the carboxyl side of
the double bond
- ex: palmitoleic acid
- 16 carbons
- double bonds between carbons 9 and 10
16 : 1 : 9 or 16 : 1 : 9
ii. ________ Name
- number of carbon atoms
- number of double bonds (unless it has only 1)
- suffix -_____
- ex: palmitoleic acid cis-9
-hexadecenoic acid
linoleic acid
- 18 carbons
- 2 double bonds
cis-9
, 12
-octadecadienoic acid
iii. _______ (ω) Numbering System
- terminal methyl group is the -carbon regardless of the chain length
- carbons in a fatty acid can also be counted beginning at the omega (or________) end of the
- suffix -enoic
- carbons in a fatty acid can also be counted beginning at the omega (or methyl terminal) end of the
b. Structure
- double bonds are spaced at 3 carbon intervals
i. Double Bonds
- in naturally occurring fatty acids
ii. Trans Double Bonds
- unnatural
- predominate in fatty acids found in ______ and other foods where ______ hydrogenation of vegetable oils is used in their preparation
- partial hydrogenated fatty acids are ___ at ______ temperatures
- _______ membrane fluidity when incorporated into phospholipids that constitute membranes (similar to saturated fatty acids found in ____ fat)
- associated with increased risk of ______ (also saturated fatty acids)
i. Cis Double Bonds
- predominate in fatty acids found in margarine and other foods where partial hydrogenation of vegetable oils is used in their preparation
- partial hydrogenated fatty acids are solid at cool temperatures
- decrease membrane fluidity when incorporated into phospholipids that constitute membranes (similar to saturated fatty acids found in butter fat)
- associated with increased risk of atherosclerosis (also saturated fatty acids)
c. Subdivisions (unsatturated FA)
i. _______________ ( _______________, _______________)
- contain 1 double bond
ii. _______________ ( _______________, _______________)
- contain 2 or more double bonds
iii. ______________
- derived from eicosa- (20 carbons) polyenoic fatty acid
iiia. Comprise:
- ______________ (LTs)
- ______________ (LXs)
- ______________ :
- ______________ (PG)
- ______________ (PGIs)
- ______________ (TXs)
i. Monounsaturated (Monoethenoid, Monoenoic)
ii. Polyunsaturated (Polyethenoid, Polyenoic)
iii. Eicosanoids
iiia. Comprise
- leukotrienes (LTs)
- lipoxins (LXs)
- prostanoids
- prostaglandins (PG)
- prostacyclins (PGIs)
- thromboxanes (TXs)
C. Source (Fatty Acids)
1. _____Fatty Acids
- can be synthesized from products of glucose oxidation
2. _____ Fatty Acids
- must be obtained from the diet especially _____ and ____ families
- no human enzymes that can introduce doubles bonds beyond carbon __ of a fatty acid chain and all double bonds introduced are separated by ___-carbon intervals
- fatty acid elongation only occurs by 2-carbon addition impossible to synthesize ______ certain polyunsaturated fatty acids
1. Nonessential Fatty Acids
2. Essential Fatty Acids
- must be obtained from the diet especially linoleic and linolenic families
- no human enzymes that can introduce doubles bonds beyond carbon 9 of a fatty acid chain and all double bonds introduced are separated by 3-carbon intervals
- fatty acid elongation only occurs by 2-carbon addition impossible to synthesize de novo certain polyunsaturated fatty acids
D. Physical Properties
1. Amphipathic
- detergent-like
- nonpolar (__) and polar (____) ends
- _____ end associated with water
- _____ end associated with hydrophobic phase
2. Melting Point (Melting Temperature)
- factors that increase melting temperature (Tm)
- increased the chain length
- addition of double bonds (degree of unsaturation)
- longer chain length ______ melting point
- greater number of double bonds _____ melting point
presence of unsaturated fatty acids in membrane lipids ____ nature
- nonpolar (-CH3) and polar (-COOH) ends
- polar end associated with water
- nonpolar end associated with hydrophobic phase
- longer chain length higher melting point
- greater number of double bonds lower melting point
presence of unsaturated fatty acids in membrane lipids fluid nature
3. Sensitivity to Oxidation
a. Saturated Fatty Acids
- relatively _____ to oxidation outside the body
b. Unsaturated Fatty Acids
- _____ but _____ oxidized in the presence of _____ _____
- relatively resistant to oxidation outside the body
- slowly but spontaneously oxidized in the presence of air rancidification
E. Branched-Chain Fatty Acids
- almost all fatty acids in mammalian tissues are of the ________-chain variety
1. _______-Chain Fatty Acids in Nature
a. ___ Acid (3, 7, 11, 15-_______ _______Acid)
- significant amounts in ____ products
- inability to degrade accumulation in plasma and tissues (______ disease)
- almost all fatty acids in mammalian tissues are of the straight-chain variety
1. Branched-Chain Fatty Acids in Nature
a. Phytanic Acid (3, 7, 11, 15-Tetramethyl Palmitic Acid)
- significant amounts in dairy products
- inability to degrade accumulation in plasma and tissues (Refsum’s disease)
F. Essential Fatty Acids
1. ______ Acid
- precursor of arachidonic acid
- deficiency arachidonic acid becomes essential
2. ______ Acid
- precursor of other ____ fatty acids important for
- g_____
- d_____
a. Deficiency
_____
_____ learning behaviors
1. Linoleic Acid
2. Linolenic Acid
- precursor of other w-3-fatty acids important for
- growth
- development
decreased vision
altered learning behaviors
B. Sources of Acetyl CoA (acetyl coenzyme A)
1. ______
a. Acetyl CoA
- from glucose oxidation via ______
1. Cytosol
- from glucose oxidation via glycolysis
2. Mitochondrial (The Citrate Shuttle System and Malic Enzyme)
- ___ portion of acetyl CoA cannot pass the mitochondrial membrane should be ______
a. Mitochondrial Acetyl CoA
- produced by:
- oxidation of ______ or
- degradation of:
-_____ acids
-_____ bodies
- _____ acids
- CoA portion of acetyl CoA cannot pass the mitochondrial membrane should be transported
- oxidation of pyruvate or
- fatty acids
- ketone bodies
- amino acids
b. Reactions
i. ______ catalyzes the reaction of acetyl CoA with ________(………………) form _____in the mitochondria
ii. Citrate is transported into the cytosol by a _________ system
iii. Citrate reacts with CoA in the cytosol _____ and _____
- catalyzed by citrate ______
- requires ______
- occurs when mitochondrial citrate concentration is ______
- observed when __________ is inhibited by the presence of large amounts of ATP accumulation of citrate and isocitrate (large amounts of ATP + high citrate
concentration enhancement of this pathway to occur)
iv. OAA is converted to_______ by an NAD+
-dependent cytosolic malate dehydrogenase
v. Malate is decarboxylated ______
- catalyzed by malic enzyme
- forms ______ from NADP+
vi. ___ is transported into the mitochondria by an ____ transport system
vii. OAA can be regenerated from pyruvate by the actions of ___________ which requires ________
i. Citrate synthase catalyzes the reaction of acetyl CoA with OAA (Oxaloacetic acid) form citrate in the mitochondria
ii. Citrate is transported into the cytosol by a tricarboxylic acid transport system
iii. Citrate reacts with CoA in the cytosol acetyl CoA and OAA
- catalyzed by citrate lyase
- requires ATP
- occurs when mitochondrial citrate concentration is high
- observed when isocitrate dehydrogenase is inhibited by the presence of large amounts of ATP accumulation of citrate and isocitrate (large amounts of ATP + high citrate
iv. OAA is converted to malate by an NAD+
v. Malate is decarboxylated pyruvate
- forms NADPH from NADP+
vi. Pyruvate is transported into the mitochondria by an active transport system
vii. OAA can be regenerated from pyruvate by the actions of pyruvate carboxylase which requires ATP
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