Lipid Metabolism

When blood glucose levels are high, beta cells of the pancreas are triggered to produce an anabolic hormone,  

Insulin stimulates   mainly in the liver.

Under aerobic conditions, glucose is oxidized, a process that results in the production of   inside the  

 a two-carbon compound is the precursor that is required for fatty acid synthesis.

Fatty acid synthesis occurs in the 

What are the two compounds required for fatty acid synthesis?
1. 
2.  

The precursor acetyl CoA   be transported directly from the mitochondria into the cytosol, due to the  .

Transport of acetyl CoA into cytosol?

Citrate is carried into the cytosol by a citrate carrier. Then,   (enzyme) converts citrate into   and  .   +  converts   to  .   (which produces  ) converts malatae into  . Pyruvate can then enter the mitochondria using a pruvate transporter. Using   and  ), pyruvate becomes OAA. The OAA can then be combined with   using  to form citrate.

In addition to acetyl CoA, fatty acid biosynthesis
also requires a 

What are the sources of NADPH for fatty acid synthesis?
1.  
2.  

What is the rate limiting step and commited step in fatty acid synthesis?
 

Acetyl CoA carboxylase has  
moiety which participates in the
carboxylation reaction in forming
 

Steps in Synthesis of Malonyl COA
1. Carboxylation of  
  +   +   ->  
2. Carboxylation of  
  +  ->   +  

Consumption of raw egg is not
recommended since raw egg
contains a protein called  
which can tie up the   which would adversely impact  

What three things does acteyl CoA carboxylase need?
1.  
2.  
3.  

Acetyl CoA carboxylate synthesizes  

 is a committed metabolite that can enter only the fatty acid biosynthetic
pathway.

Fatty acid synthase (FAS) is a multi-enzyme complex that is
composed of   domains that are 

What are the three steps of the catalytic events of the fatty acid synthase (FAS)?
1. After condensation, acteoacteyl group is reduced to   in 3 steps while still attached to  
2. The   is transferred to   and   enters and gets attached to  
3.  occurs again and new 6 carbon gets   while attached to  
4. Cycle repeats until  

Order of Enzyme Domians
 
 
 
 
 
 
 

What is AT?

What is MT?

What is CE?

When blood glucose levels are high, beta cells of the pancreas are triggered to produce an anabolic hormone,  

What is ER?

What is KR?

What is TE?

  is the prosthetic group that
anchors the growing fatty acid chain during synthesis

 Phosphopantetheine is covalently attached to   protein

NADPH is utilized in the  

 domain cleaves off the final product,  , from the fatty acid
synthase enzyme complex. Occasionally the fatty acyl chain goes through one more cycle, and
it gets cleaved off as  

In mammals during lactation, mammary glands express  , an independent protein that interacts with the fatty acid synthase complex and causes the  of fatty acids  ,  , and 

Unsaturated fatty acids that can be synthesized de novo are called  

Humans do not have
enzymes that can introduce   beyond  

Stoichometry of palmitate synthesis

Polyunsaturated fatty acids linoleic, 18:2
(9,12) and linolenic,18:3 (9,12,15) are
therefore   that must be
supplied in the diet.

Linoleic acid is the precursor for the
biosynthesis of   which is
 .

  the end product of fatty
acid synthase can be further elongated
and/or desaturated by separate enzymes
that are located in the   and
 .

The desaturase that is located in the
endoplasmic reticulum using  ,  , and   forms  or  respectively.

The reaction that takes place with the desaturase in the ER uses a complex of which three membrane bound enzymes?

Draw desaturase reaction

Electron Transport Chain reaction in the desaturation of  

Triglycerides are synthesized in the liver and are
stored in 

Acetyl CoA can enter the TCA cycle to be
metabolized. However,   cannot
enter the TCA cycle directly

Triglycerides that are formed in the liver are packaged with proteins to form , which are then transported into  . Once inside the adipose tissue triglycerides are released from .

When the energy requirements are high, the adipose-stored triglycerides are   into  and  

Free fatty acids are
oxidized e.g. thru
(b-oxidation) to produce
 ,  , and  

The released fatty acids bind to
  and send to the
liver for  .

Pancreatic lipase (the enzyme that is involved in fat digestion) as part of food digestion is inhibited by the pharmacological compound 

Fatty acids must be transported from the   into the  where the
actual degradation occurs

Fatty acids can be   and   for transport

How are free fatty acids activated?

Activating fatty acid into fatty acid COA requires   to be consumed.

The fatty acyl CoA from the cytosol is converted into a
transportable derivative called  
catalyzed by the enzyme  

Fatty acyl-carnitine enters the mitochondria through a specific carrier system into
the mitochondrial matrix, where it gets converted back to   catalyzed by the enzyme .

People with carnitine or carnitine palmitoyltransferase (CPT) deficiency are unable to
  like palmitic acid.

In adults with a carinitive palitoyltransferase deficiency, what is the most common effect? Newborn?

Where do the NADH and FADH2 produced by b-oxidation go?

Where does the acteyl CoA produced by b-oxidation go?

What are the 4 steps of B oxidation?
1.  
2.  
3.   (using  )
4.  , using  

Each cycle of beta oxidation produces what?
1 molecule each of  ,  , and  

Each NADH through the electron transport system produces  
molecules of ATP and FADH2 produces  moles of ATP

What is the total energy yeild of palmitate?

Free fatty acid must be converted to  
before it undergoes B-oxidation.

Fatty acid activation to fatty acyl CoA  , therefore deducting that, the net ATP yield is
( ).

Acetyl CoA can enter the TCA cycle to be
metabolized. However,   cannot
enter the TCA cycle directly

What are the 3 steps of propinonyl coA metabolism?
1.   through TCA cycle is converted to  
2. Process produces  ,  , and  
3. One mole of succinyl coa is   moles ATP (  because of   step)