Exam 2 Fatty Acid Synthesis

Front 1

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

What are the other 2 places in which FA synthesis can occur?

Back 1

liver
adipose tissue
mammary glands

Front 2

Dietary ... serves as the major source of carbon in the synthesis of fatty acids.

Back 2

glucose

Front 3

glucose must first be converted to ..., which provides the 2-carbon units that condense to form a FA chain

Back 3

acetyl CoA

Front 4

which enzyme is found only in the mitochondria?

Back 4

pyruvate dehydrogenase

Front 5

acetyl CoA cannot cross the mitochondrial membrane, so it must be converted into ... first

Back 5

citrate

Front 6

synthesis of fatty acids occur in the ...

Back 6

cytosol

Front 7

synthesis occurs with the growing fatty acid chain attached to an ...

Back 7

acyl carrier protein (ACP)

Front 8

synthesis in higher organisms is mediated by a single very large protein called ...

Back 8

fatty acid synthase (FAS)

Front 9

synthesis occurs by the addition of 2 carbon units which are derived from acetyl-CoA, but the actual donor is ...

Back 9

malonyl-CoA

Front 10

During synthesis of fatty acids, ... is used as a reducing agent

Back 10

NADPH

Front 11

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

Back 11

16

Front 12

once taken up by a cell, glucose is first converted into ... in the cytosol through glycolysis.

Back 12

pyruvate

Front 13

pyruvate then enters the mitochondria, where it can be converted into one of 2 products: ... produced by pyruvate dehydrogenase, or ... produced by pyruvate carboxylase.

Back 13

acetyl-CoA
oxaloacetate (OAA)

Front 14

Citrate is continuously synthesized and transported out of the mitochondria into the cytosol through ... of both acetyl-CoA and OAA.

Back 14

reciprocal regulation

Front 15

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.

Back 15

condensation

Front 16

Once in the cytoplasm, citrate is converted back into acetyl-CoA and OAA by ...

Back 16

citrate lyase

Front 17

the OAA is then recycled and reused again by the ...

the recycling of OAA involves its conversion into ..., and finally back to pyruvate

Back 17

mitochondria
malate

Front 18

The recycling of OAA produces 2 key players: ... and ...

Back 18

NAD+
NADPH

Front 19

NADPH is a ... molecule (adds H+_

Back 19

reducing

Front 20

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.

Back 20

malic enzyme
pentose phosphate pathway

Front 21

after consumption of carbohydrates, ... levels go up

Back 21

insulin

Front 22

Insulin drives fatty acid synthesis in what 3 ways?

Back 22

-activates pyruvate dehydrogenase
-induces synthesis of malic enzyme and glucose-6-phosphate dehydrogenase
-induces synthesis of citrate lyase

Front 23

insulin activates pyruvate dehydrogenase, leading to an increase in the production of ...

Back 23

acetyl-CoA

Front 24

insulin induces synthesis of malic enzyme and glucose-6-phosphate dehydrogenase, both of which increase production of ... needed for fatty acid synthase

Back 24

NADPH

Front 25

insulin induces synthesis of citrate lyase, thereby increasing cytosolic levels of ... and increasing the recycling of ...

Back 25

acetyl-CoA
OAA

Front 26

step 1 in FA synthesis is:

Back 26

conversion of glucose to acetyl-CoA

Front 27

step 2 in FA synthesis is:

This step is the ... in fatty acid synthesis and is heavily regulated

Back 27

conversion of acetyl-CoA into malonyl CoA

rate limiting step

Front 28

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.

Back 28

immediate

Front 29

The conversion of acetyl-CoA into Malonyl CoA requires which 4 main players?

Back 29

acetyl-CoA carboxylase
biotin
CO2
ATP

Front 30

which enzyme is targeted when you want to increase or decrease fatty acid synthesis?

Back 30

acetyl CoA carboxylase

Front 31

In which 3 ways is acetyl-CoA's activity regulated?

Back 31

phosphorylation
allosteric modification
induction/repression of its synthesis

Front 32

insulin stimulates ... of acetyl-CoA carboxylase-P (inactive)

Back 32

dephosphrylation

Front 33

step 3 in FA synthesis is ...

Back 33

formation of fatty acid synthase complex

Front 34

Fatty acid synthase sequentially adds 2-C units from malonyl CoA to the growing fatty acyl chain to form ...(C16:0)

Back 34

palmitate

Front 35

After the addition of each 2-C unit, the growing chain undergoes 2 ... reactions that require ...

Back 35

reduction
NADPH

Front 36

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)

Back 36

acyl carrier protein (ACP)
phosphopantetheine

Front 37

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 ...

Back 37

7
malonyl-CoA

Front 38

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.

Back 38

acetyl moiety
malonyl moiety

Front 39

In fatty acid synthase:
-NADPH reduction results in original acetyl group elongated by # carbons

Back 39

2

Front 40

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

Back 40

malonyl

Front 41

Elongation of the fatty acid chain occurs via 4 recurring reactions, which are...

Back 41

Condensation
reduction
dehydration
reduction

Front 42

what reaction combines 2 chains together?

Back 42

condensation

Front 43

what reaction needs NADPH?

Back 43

reduction

Front 44

what reaction removes water?

Back 44

dehydration

Front 45

elongation of fatty acids is mediated by what?

Back 45

Fatty acid synthase complex

Front 46

The final end product of the fatty acid synthase complex is the saturated fatty acid ... (C16:0).

Back 46

palmitate

Front 47

palmitate can then be used, along with malonyl CoA and NADPH, to form ... fatty acids and ... fatty acids within the endoplasmic reticulum.

Back 47

longer chain
unsaturated

Front 48

To make other fatty acids, palmitate must first be activated by converting it into ...

Back 48

palmityl-CoA

Front 49

Palmityl-CoA can then be elongated, two carbons at a time with ... serving as the 2-C donar and ... providing the reducing equivalents.

Back 49

malonyl CoA
NADPH

Front 50

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.

Back 50

coenzyme A

Front 51

Desaturation of fatty acids requires what 3 things?

Back 51

O2
NADH
cytochrome b5

Front 52

The desaturation of fatty acids occurs in the ... and results in oxidation of both the fatty acid and NADH.

Back 52

SER

Front 53

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)

Back 53

9 and 10
palmitoleic acid
oleic acid

Front 54

what are the 3 main families of unsaturated fatty acids, each of which differs according to the position of the carbon double bonds?

Back 54

omega-3 family
omega-6 family
omega-9 family

Front 55

The usual way to count unsaturated fatty acids is to start at the ... end (methyl end) and not the alpha end (carboxylic acid end)

Back 55

omega

Front 56

polyunsaturated FAs with double bonds 3 carbons from the methyl end and 6 carbons from the methyl end are required for synthesis of ...

Back 56

eicosanoids

Front 57

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)

Back 57

linoleic acid (LA)
alpha-linolenic acid (ALA)

Front 58

-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)

Back 58

double bonds
desaturase

Front 59

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)

Back 59

starting point

Front 60

arachidonic acid reduces ...

Back 60

inflammation

Front 61

arachidonic acid is a precursor for ... and ...

Back 61

prostaglandins
eicosanoids

Front 62

you need ... acid to make arachidonic acid

Back 62

linoleic acid

Front 63

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.)

Back 63

omega-6 fatty acids

Front 64

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

Back 64

omega-3 fatty acids

Front 65

-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

Back 65

anti-inflammatory
cardiovascular
balanced proportion

Front 66

If you have growth retardation, skin lesions, reproductive failure, and fatty liver, these are symptoms of what deficiency?

Back 66

omega 6

Front 67

if you have learning deficiencies, imparied visual acuity, and depression, you have what kind of deficiency?

Back 67

omega 3

Front 68

step 1 in the synthesis of triglycerides is ...

Back 68

the generation of glycerol 3-phosphate

Front 69

adipose tissue can only produce glycerol-3-phosphate from glucose via ...

Thus, adipose tissue can only store fat when glucose is readily available.

Back 69

dihydroxyacetone phosphate (DHAP)

Front 70

Fatty acids are stored for future use as ... in all cells, but primarily in adipocytes of adipose tissue

Back 70

triacylglycerols/triglycerides

Front 71

triacylglycerols constitute molecules of glycerol to which 3 fatty acids have been ...

Back 71

esterified

Front 72

the fatty acids present in triacylglycerols are predominantly ...

Back 72

saturated

Front 73

The major building block for the synthesis of triacylglycerols, in tissues other than adipose tissue, is ...

Back 73

glycerol

Front 74

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.

Back 74

backbone

Front 75

step 2 in synthesis of triglycerides is:

Back 75

activation of fatty acids, forming fatty acyl CoA

Front 76

step 3 in the synthesis of triglycerides is:

Back 76

formation of phosphatidic acid

Front 77

step 4 is :

Back 77

formation of diacylglycerol and triacylglycerols

Front 78

step 5:

Back 78

transport and/or storage of triglycerides

Front 79

step 2: fatty acid activation with ... and ..., forming a fatty acyl CoA

Back 79

ATP
fatty acyl CoA synthetase

Front 80

step 3: glycerol 3-phosphate reacts with fatty acyl CoA forming ..., which then dephosphorylates forming diacylglycerol (DAG) in the 4th step

Back 80

phosphatidic acid

Front 81

step 4: forming diacylglycerol, then adding a 3rd and final fatty acyl CoA, forming a ...

Back 81

triacylglycerol

Front 82

step 5: triglyceride is incorporated into ... particles or stored as adipose

Back 82

VLDL

Front 83

what is a plasma lipoprotein that functions as the body's internal transport mechanism for lipids?

Back 83

VLDL

Front 84

VLDL is synthesized in the ..., and the fatty acids necessary for VLDL synthesis are obained from the ... or they are synthesized directly from ...

Back 84

liver
blood
glucose

Front 85

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

Back 85

muscle
adipose