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85 Cards in this Set

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Fatty acids are mainly synthesized in the ... whenever excess calories are ingested.

What are the other 2 places in which FA synthesis can occur?
liver
adipose tissue
mammary glands
Dietary ... serves as the major source of carbon in the synthesis of fatty acids.
glucose
glucose must first be converted to ..., which provides the 2-carbon units that condense to form a FA chain
acetyl CoA
which enzyme is found only in the mitochondria?
pyruvate dehydrogenase
acetyl CoA cannot cross the mitochondrial membrane, so it must be converted into ... first
citrate
synthesis of fatty acids occur in the ...
cytosol
synthesis occurs with the growing fatty acid chain attached to an ...
acyl carrier protein (ACP)
synthesis in higher organisms is mediated by a single very large protein called ...
fatty acid synthase (FAS)
synthesis occurs by the addition of 2 carbon units which are derived from acetyl-CoA, but the actual donor is ...
malonyl-CoA
During synthesis of fatty acids, ... is used as a reducing agent
NADPH
Synthesis of FAs by the FAS complex stops after # carbons have been added (palmitate) and further elongation and addition of double bonds are carried out by other systems
16
once taken up by a cell, glucose is first converted into ... in the cytosol through glycolysis.
pyruvate
pyruvate then enters the mitochondria, where it can be converted into one of 2 products: ... produced by pyruvate dehydrogenase, or ... produced by pyruvate carboxylase.
acetyl-CoA
oxaloacetate (OAA)
Citrate is continuously synthesized and transported out of the mitochondria into the cytosol through ... of both acetyl-CoA and OAA.
reciprocal regulation
citrate is formed by the ... of acetyl-CoA and OAA. This reduces the levels of acetyl-CoA in the mitochondria, thus driving pyruvate dehydrogenase to make more acetyl-CoA.
condensation
Once in the cytoplasm, citrate is converted back into acetyl-CoA and OAA by ...
citrate lyase
the OAA is then recycled and reused again by the ...

the recycling of OAA involves its conversion into ..., and finally back to pyruvate
mitochondria
malate
The recycling of OAA produces 2 key players: ... and ...
NAD+
NADPH
NADPH is a ... molecule (adds H+_
reducing
The NADPH generated by the ... during the recycling of OAA, along with the NADPH generated in the ... pathway, are used for the reduction reactions that occur later in FA synthesis.
malic enzyme
pentose phosphate pathway
after consumption of carbohydrates, ... levels go up
insulin
Insulin drives fatty acid synthesis in what 3 ways?
-activates pyruvate dehydrogenase
-induces synthesis of malic enzyme and glucose-6-phosphate dehydrogenase
-induces synthesis of citrate lyase
insulin activates pyruvate dehydrogenase, leading to an increase in the production of ...
acetyl-CoA
insulin induces synthesis of malic enzyme and glucose-6-phosphate dehydrogenase, both of which increase production of ... needed for fatty acid synthase
NADPH
insulin induces synthesis of citrate lyase, thereby increasing cytosolic levels of ... and increasing the recycling of ...
acetyl-CoA
OAA
step 1 in FA synthesis is:
conversion of glucose to acetyl-CoA
step 2 in FA synthesis is:

This step is the ... in fatty acid synthesis and is heavily regulated
conversion of acetyl-CoA into malonyl CoA

rate limiting step
Cytosolic acetyl-CoA is converted to malonyl CoA, which serves as the ... donar of the 2-carbon units that are added to the growing fatty acid chain.
immediate
The conversion of acetyl-CoA into Malonyl CoA requires which 4 main players?
acetyl-CoA carboxylase
biotin
CO2
ATP
which enzyme is targeted when you want to increase or decrease fatty acid synthesis?
acetyl CoA carboxylase
In which 3 ways is acetyl-CoA's activity regulated?
phosphorylation
allosteric modification
induction/repression of its synthesis
insulin stimulates ... of acetyl-CoA carboxylase-P (inactive)
dephosphrylation
step 3 in FA synthesis is ...
formation of fatty acid synthase complex
Fatty acid synthase sequentially adds 2-C units from malonyl CoA to the growing fatty acyl chain to form ...(C16:0)
palmitate
After the addition of each 2-C unit, the growing chain undergoes 2 ... reactions that require ...
reduction
NADPH
The fatty acid synthase complex is a large enzyme consisting of 2 identical dimers, each of which is associated with an ... that contains a ... residue (derived from the vitamin panththenic acid)
acyl carrier protein (ACP)
phosphopantetheine
Each dimer of fatty acid synthase has # different catalytic activities. These catalytic activities allow the synthase complex to carry out all the necessary steps involved in building a fatty acid from ...
7
malonyl-CoA
In fatty acid synthase:
-An ... (from acetyl CoA) and ... (from malonyl CoA) attach to the ACP phosphopantetheinyl sulfhydral group, then condense to form a 4-carbon alpha-keto acyl chain.
acetyl moiety
malonyl moiety
In fatty acid synthase:
-NADPH reduction results in original acetyl group elongated by # carbons
2
in fatty acid synthase:
-with each subsequent round of elongation, a new ... group attaches to the FAS complex and condenses with the newly forming fatty acid chain
malonyl
Elongation of the fatty acid chain occurs via 4 recurring reactions, which are...
Condensation
reduction
dehydration
reduction
what reaction combines 2 chains together?
condensation
what reaction needs NADPH?
reduction
what reaction removes water?
dehydration
elongation of fatty acids is mediated by what?
Fatty acid synthase complex
The final end product of the fatty acid synthase complex is the saturated fatty acid ... (C16:0).
palmitate
palmitate can then be used, along with malonyl CoA and NADPH, to form ... fatty acids and ... fatty acids within the endoplasmic reticulum.
longer chain
unsaturated
To make other fatty acids, palmitate must first be activated by converting it into ...
palmityl-CoA
Palmityl-CoA can then be elongated, two carbons at a time with ... serving as the 2-C donar and ... providing the reducing equivalents.
malonyl CoA
NADPH
The series of elongation reactions resemble those of fatty acid synthesis, except that the fatty acyl chain is attached to ... rather than to the phosphopantetheinyl residue of ACP.
coenzyme A
Desaturation of fatty acids requires what 3 things?
O2
NADH
cytochrome b5
The desaturation of fatty acids occurs in the ... and results in oxidation of both the fatty acid and NADH.
SER
The most common desaturation reactions involve the placement of a double bond between carbons ... and ..., resulting in conversion of palmitic acid (C16:0) to ...(C16:1, position 9) and conversion of steric acid (C18:0) to ... (C18:1, position 9)
9 and 10
palmitoleic acid
oleic acid
what are the 3 main families of unsaturated fatty acids, each of which differs according to the position of the carbon double bonds?
omega-3 family
omega-6 family
omega-9 family
The usual way to count unsaturated fatty acids is to start at the ... end (methyl end) and not the alpha end (carboxylic acid end)
omega
polyunsaturated FAs with double bonds 3 carbons from the methyl end and 6 carbons from the methyl end are required for synthesis of ...
eicosanoids
The 2 main sources of the essential amino acids are ...(C18:2, omega-6), which is converted into arachidonic acid (AA, 20:4), and ... (C18:3, omega-3), which is converted into eicosapentanoic acid (EPA, 20:5)
linoleic acid (LA)
alpha-linolenic acid (ALA)
-essential fatty acids cannot be synthesized by the body, so they must be supplied in food.
-mammals lack the ability to introduce ... in fatty acids beyond carbon 9 and 10 (lack the ... enzyme)
double bonds
desaturase
essential fatty acids form the ... for the creation of longer and more desaturated fatty acids, like docosahexaenoic acid (22:6), arachidonic acid (20:4)(precursor for icosinoids), and eicosapentaenoic acid (20:5)
starting point
arachidonic acid reduces ...
inflammation
arachidonic acid is a precursor for ... and ...
prostaglandins
eicosanoids
you need ... acid to make arachidonic acid
linoleic acid
which family of fatty acids is this?
-linoleic acid --> arachidonic acid
-precursors for prostaglandins and other eicosanoids
-pro-inflammatory mediators (play impt roles in the immune system)
-essential for development of brain and eyes, dermal support, renal function and parturition
-sources: plant oils (olive, corn, canola, sunflower, etc.)
omega-6 fatty acids
which fatty acid family is this?
-alpha-linolenic acid (ALA, 18:3)
-eicosapentaenoic acid (EPA, 20:5)
-docosahexanoic acid (DHA, 22:6)
-sources: cold water fish (like salmon), flaxseed, eggs, walnuts, grass-fed animials)
-eye and brain development and health
-reduced risk of heart disease and atherosclerosis
-decreased LDL and triglycerides, increased HDL
-reduced risk of certain cancers
-reduced risk of inflammitory and autoimmune diseases
improve memory, learning, behavior, and mood
omega-3 fatty acids
-omega-6 fatty acids are mostly pro-inflammatory, while the omega-3 fatty acids are ...
-The ingested ratio of omega-6 to omega-3 fatty acids is important in maintaining ... health
-this necessitates that omega-3 and omega-6 be consumed in a ...; the ideal ratio of omega 6: omega 3 being 3:1 or 5:1
anti-inflammatory
cardiovascular
balanced proportion
If you have growth retardation, skin lesions, reproductive failure, and fatty liver, these are symptoms of what deficiency?
omega 6
if you have learning deficiencies, imparied visual acuity, and depression, you have what kind of deficiency?
omega 3
step 1 in the synthesis of triglycerides is ...
the generation of glycerol 3-phosphate
adipose tissue can only produce glycerol-3-phosphate from glucose via ...

Thus, adipose tissue can only store fat when glucose is readily available.
dihydroxyacetone phosphate (DHAP)
Fatty acids are stored for future use as ... in all cells, but primarily in adipocytes of adipose tissue
triacylglycerols/triglycerides
triacylglycerols constitute molecules of glycerol to which 3 fatty acids have been ...
esterified
the fatty acids present in triacylglycerols are predominantly ...
saturated
The major building block for the synthesis of triacylglycerols, in tissues other than adipose tissue, is ...
glycerol
DHAP can also serve as a ... precursor for triacylglycerol synthesis in tissues other than adipose, but does so to a much lesser extent than glycerol.
backbone
step 2 in synthesis of triglycerides is:
activation of fatty acids, forming fatty acyl CoA
step 3 in the synthesis of triglycerides is:
formation of phosphatidic acid
step 4 is :
formation of diacylglycerol and triacylglycerols
step 5:
transport and/or storage of triglycerides
step 2: fatty acid activation with ... and ..., forming a fatty acyl CoA
ATP
fatty acyl CoA synthetase
step 3: glycerol 3-phosphate reacts with fatty acyl CoA forming ..., which then dephosphorylates forming diacylglycerol (DAG) in the 4th step
phosphatidic acid
step 4: forming diacylglycerol, then adding a 3rd and final fatty acyl CoA, forming a ...
triacylglycerol
step 5: triglyceride is incorporated into ... particles or stored as adipose
VLDL
what is a plasma lipoprotein that functions as the body's internal transport mechanism for lipids?
VLDL
VLDL is synthesized in the ..., and the fatty acids necessary for VLDL synthesis are obained from the ... or they are synthesized directly from ...
liver
blood
glucose
one of the primary roles of VLDL is to deliver triglycerides to cells, particularly ... cells and ...

These triglycerides can then be used for energy storage
muscle
adipose