Dealing with a double bond on an odd carbon...

The mitochondrian in these myocytes is one cell type
that metabolizes fatty acids--including odd ones:)

When metabolizing a fatty acid with a double bond that is on the gamma carbon instead of the beta carbon, there will be an isomerase enzyme that causes a shift of the double bond so that you can continue to oxidize the beta carbon.

LINK:  DEALING WITH THE ODD DOUBLE BOND

Beta Oxidation

...OX-idation

Beta Oxidation was first discovered when an OX ingested a BETA fish...

BETA...

Beta oxidation is incredible stuff.  Glycolysis to the Electron Transport Chain is classic metabolism.  Now we are going to be branching out to other mechanisms of metabolism that weave themselves into the classic Glycolysis-Pyruvate Dehydrogenase Complex-Citric Acid Cycle-Electron Transport Chain/ATP-Synthase.  Beta oxidation is the first thread we are going to follow in the big picture tapestry.

Beta Oxidation occurs in the matrix of the mitochondria, but first we need to walk through the steps the body takes to get a fatty acid to a myocyte or an adipocyte:  HOW FAT GETS TO THE CELL!!!!!

Now that the fatty acids are in the cell cytosol, we need to get the fatty acids into the mitochondrial matrix.  The fatty acids are tagged for diffusion into the matrix and then, with the use of carnitine, are taken into the matrix:  THE CARNITINE REACTION!!!!!

Now that the fatty acids are FINALLY in the matrix, Beta Oxidation can occur.  Remember that the point of metabolism is to create a metabolite that resembles something from the "classic metabolism" we've already studied.  In the case of Beta Oxidation, we are going to create acetyl-CoA from a fatty acid, and thereby feed the Citric Acid Cycle:  BETA-OXIDATION!!!!!

ECT Take Two

Hey everyone, I thought I'd give the ETC another go.  If you thought the first pair of ETC tutorials had to much information in too little space, I tried to spread it out a bit in this one:)

Also, the typed intro the electron transport chain is on the previous post, this one just has a couple different videos.

Simplified ETC:  WHERE THE SIDEWALK ENDS--TAKE TWO  

Detailed ETC:  WHERE THE SIDEWALK ENDS--TAKE TWO

I always think of EAC when we talk about ETC:)

The Electron Transport Chain!!!

Iron is one of the carriers:)

There are a series of dams that
harness the potential energy
of the water.  

This is where the magic happens

The "combustion" of glucose concludes here.  The electrons that were harnessed by the MANY redox reaction along the way are going to get put to work.  The electron transport chain has a series of complexes that allows the electrons to be passed along from NADH/H+ and FADH2 to O2 for the creation of water.  It is truly inspiring.

Simplified Electron Transport Chain:  WHERE THE SIDEWALK ENDS:)
Detailed Electron Transport Chain:  WHERE THE SIDEWALK ENDS:)

The Citric Acid Cycle--an overview of...THE HUB

The citric acid cycle is the "hub" of metabolism; meaning that most every other type of catabolism has the goal of looking like one of the intermediates in the cycle.  After pyruvate goes through the pyruvate dehydrogenase complex another CO2 is lost, and we are now down to the 2 carbon acetyl-CoA.  This two carbon molecule joins with
oxaloacetate to form citrate...and
so it begins:)

There's two ways to learn this, first, you could approach it like memorizing the C section of the phone book... that would be boring... OR if you focus on the principles of why and how, you'll be able to                     derive the steps.

The citric acid cycle is the "hub" of metabolism for a reason, and you'll need to be fluent with the intermediate products, not just familiar, in order to be able to stay  not feel lost in subsequent lectures.


Here are the links...

Simplified CAC:  THE HUB OF METABOLISM!!!

Detailed CAC:  THE HUB OF METABOLISM!!!

Pyruvate Dehydrogenase Complex

Here's more on "Step Two"

The pyruvate dehydrogenase complex is a complex of three different enzymes.  This is another site of oxidation which means that we will harness that energy in an NAD+ molecule like we always do (except when we don't:)

One cool thing to notice...  the actual reduction of NAD+ happens many steps after the carbonyl on the pyruvate has lost its CO2

This is just brief representation of what happens:  PYRUVATE DEHYDROGENASE COMPLEX!!!

Glycolysis--Step 6 Enzymatically

Glyceraldehye-3-phosphate Dehydrogenase is the enzyme used in step six for the conversion of Glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate.

Remember that an enzyme is a three dimensional structure that binds (sometimes covalently) a substrate and enables a reaction to occur at a much more controlled if not faster rate.

So put on your headlamps and go into the active site...:)






Here's the link for the stepwise mechanism of Glyceraldehyde-3-phosphate dehydrogenase:  ACTIVE SITE!!!

Glycolysis-an overview (cont.)

Here is the payoff phase of glycolysis.  Here is where ATP (the ultimate goal of metabolism) and NADH (the almost ultimate goal of metabolism) production begins.  ATP is primarily made in the electron transport chain, and NADH fuels the ETC.  Remember that with each oxidation reaction (the dehydrogenase reactions...) we harvest a little bit more of the energy found in a glucose molecule.

Here's the link for the payoff phase of glycolysis (steps 6-10):  THE PAYOFF PHASE

"My name is Captain Jack Sparrow, and I approve this message"

Glycolysis-an overview

"Hi, my name is Penguinone"

This link will walk through the big picture of glycolysis and the players involved:

1.  NAD+
2.  FAD
3.  First 5 steps of glycolysis (the preparatory phase--remember it's preparatory because we are not making any ATP, which is our ultimate goal of metabolism, nor are we making any NADH, which is almost the ultimate goal of metabolism.  Remember that NADH is the fuel for the H+ gradient for the electron transport chain)

Here's the link:  GYCOLYSIS-FIRST 5 STEPS

(Sometimes it's hard to talk, think and write at the same time, so bear with me:)