Web Site of Info to Explain Metabolism

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Specializes in Community Health, Med-Surg, Home Health.

I am no longer a student, but I do enjoy reading about anatomy at this point, where I can make some associations about the disease processes I teach about. One of the subjects that always plagued me is metabolism. After glucose breaks down to pyruvic acid, I am lost. I want to know this because I somehow see how this can affect diabetes and other illnesses. Does anyone have essential information to explain this process to me?

Greatly appreciated!

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Do you have specific areas that you want to know about?

After glycolysis, PA will enter the TCA cycle. Hydrogen from the break down f PA is then used to create a gradient and create PMF. The final steps of ATP production occur because of PMF and the gradient created in the ETC.

I find, you can split this into several categories.

1) Glycolysis

2) TCA Cycle

3) ETC & PMF

3) Specific enzymes and transport molecules involved. NAD and FAD for example

You should find several online biology sites that explain the process and even some that have diagrams and pictures.

Again, are there specific areas of this process that interest you?

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i am not sure if this is what your looking for, i believe it may be so i am posting a link in hopes it is what your looking for:

http://www.emc.maricopa.edu/faculty/farabee/biobk/biobookglyc.html

take care!

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Specializes in Community Health, Med-Surg, Home Health.

I get lost even listing the process of metabolism for some reason...it is like I have a mental block trying to comprehend. Thanks for the sites!

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Break it down into smaller chunks to help with the understanding.

First, we have glycolysis.

Glycolysis occurs in the cytosol of the cell. (within the cell after glucose enters but not within the mitochondria)

Glucose enters glycolysis and pyruvic acid is the finished product. Four ATP molecules result from glycolysis, but glycolysis uses two of them. At the end of glycolysis, two things can happen to the pyruvic acid.

One: We are in an aerobic (oxygen present) environment and pyruvic acid will enter the mitochondria and begin the TCA or Krebs cycle.

Two: We are in an anerobic environment and pyruvic acid cannot go through the aerobic pathways, thus we have lactic acid produced.

Lets assume we are in an aerobic environment?

Next, we have the Krebs/Citric Acid/ TCA Cycle. (What ever name you want to attach to this process, all three are proper names.)

The TCA cycles occurs within the mitochondria. Essentially, pyruvic acid enters and is immediately turned into Acetyl CoA. Acetyl Co A is broken down into citric acid. Then, through several steps, the atoms of citric acid are rearranged and turned into intermediate molecules. Basically, we break acetic acid down by pulling out carbon molecules. During all of this busy work, hydrogen atoms are also released. Transport molecules called NAD and FAD pick up the hydrogens and bring them to the electron transport chain. In addition, carbon dioxide is released as a waste product. This is where we have Co2 produced in our body.

Would you believe that through all of this mess, only one ATP is produced? So, we still only have 5 ATP that we have produced. But, we subtract two because two were used during glycolysis. So, we only have 3 useable ATP molecules so far.

Finally, we have the electron transport chain (ETC).

Remember, we had all of that hydrogen being taken away from the TCA cycle by the molecules NAD and FAD? Well, this is where they bring the hydrogen. Like the TCA cycle the ETC cycle occurs within the mitochondria. Deep within the mitochondria actually.

The easiest way of looking at the ETC is like this:

The hydrogen is combined with molecular oxygen and with the energy produced from this process, we can attach extra phosphate groups to ADP. Once this occurs, ADP is transformed into ATP. This is where the rest of the 36 useable ATP molecules are produced from a single pass through cellular respiration. You can also see why aerobic respiration is so important in producing adequate amount of ATP.

Does this help?

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Specializes in Community Health, Med-Surg, Home Health.
Break it down into smaller chunks to help with the understanding.

First, we have glycolysis.

Glycolysis occurs in the cytosol of the cell. (within the cell after glucose enters but not within the mitochondria)

Glucose enters glycolysis and pyruvic acid is the finished product. Four ATP molecules result from glycolysis, but glycolysis uses two of them. At the end of glycolysis, two things can happen to the pyruvic acid.

One: We are in an aerobic (oxygen present) environment and pyruvic acid will enter the mitochondria and begin the TCA or Krebs cycle.

Two: We are in an anerobic environment and pyruvic acid cannot go through the aerobic pathways, thus we have lactic acid produced.

Lets assume we are in an aerobic environment?

Next, we have the Krebs/Citric Acid/ TCA Cycle. (What ever name you want to attach to this process, all three are proper names.)

The TCA cycles occurs within the mitochondria. Essentially, pyruvic acid enters and is immediately turned into Acetyl CoA. Acetyl Co A is broken down into citric acid. Then, through several steps, the atoms of citric acid are rearranged and turned into intermediate molecules. Basically, we break acetic acid down by pulling out carbon molecules. During all of this busy work, hydrogen atoms are also released. Transport molecules called NAD and FAD pick up the hydrogens and bring them to the electron transport chain. In addition, carbon dioxide is released as a waste product. This is where we have Co2 produced in our body.

Would you believe that through all of this mess, only one ATP is produced? So, we still only have 5 ATP that we have produced. But, we subtract two because two were used during glycolysis. So, we only have 3 useable ATP molecules so far.

Finally, we have the electron transport chain (ETC).

Remember, we had all of that hydrogen being taken away from the TCA cycle by the molecules NAD and FAD? Well, this is where they bring the hydrogen. Like the TCA cycle the ETC cycle occurs within the mitochondria. Deep within the mitochondria actually.

The easiest way of looking at the ETC is like this:

The hydrogen is combined with molecular oxygen and with the energy produced from this process, we can attach extra phosphate groups to ADP. Once this occurs, ADP is transformed into ATP. This is where the rest of the 36 useable ATP molecules are produced from a single pass through cellular respiration. You can also see why aerobic respiration is so important in producing adequate amount of ATP.

Does this help?

Eureka!! :bow::yeah::up::cheers::balloons::thankya::monkeydance::clpty:

Hope I didn't go overboard with the appreciation, but this is exactly what I was asking for, and it finally makes sense! Thank you!

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Not a problem.

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