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Does anyone have an easy way to explain it??? I just want to cry when I see anything related to the Krebs cycle. 
Krebs cycle
- Thread starter karakhanyan
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Does anyone have an easy way to explain it??? I just want to cry when I see anything related to the Krebs cycle.
lol... hmm, that's actually a really hard one to answer...
stuff you should know from the top of your head:
glycolysis is in cytosol
krebs is in mito
36-38 atps
ETC is between the wall and the intermembrane of the mito
postive and negative enforcement
okay, this is a lot harder than I thought it would be...do you have a specific question about respiration?
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Here's an extremely oversimplified way to think about it; you can fill in details and technically accuracy later.
Glyolysis and Cellular Respiration are about converting glucose into energy. As you know, the formula for respiration is C6 H12 O6 + 6O2 --> 6CO2 + 6H2O
Glucose is a 6-carbon molecule, and there is energy holding it together. Carbon dioxide is a 1-carbon molecule.
Glycolysis is process that turns the 6-carbon glucose into two 3-carbon pyruvate molecules. This process results in a little bit of usable energy (this energy is stored in the bonds of a molecule called ATP).
Between Glycolysis and the Kreb's Cycle, each of these 3-carbon pyruvate molecules becomes a 2-carbon molecule called Acetyl CoA. The 1-carbon is removed as a molecule of CO2, and some energy is released (this energy is stored in the bonds of a molecule called NADH)
The entire Kreb's cycle is just a way to convert each of the 2-carbon Acetyl CoA molecules into 1-carbon CO2 molecules, and the extra energy holding together the larger 2-carbon molecule is stored in the bonds of small molecules (the main one is called NADH).
In a way, you can think of Kreb's cycle as a catalyst for this simple breakdown of a 2-carbon molecule to a 1-carbon molecule (CO2). This process starts with a 4-carbon molecule (Oxaloacetate) binding to the 2-carbon molecule, and after the two CO2 + energy are released, it is left with the same 4-carbon molecule (Oxaloacatete)
The electron transport chain is a way to transfer the energy from the bonds of these small molecules (like NADH) into bonds of ATP molecules.
Glyolysis and Cellular Respiration are about converting glucose into energy. As you know, the formula for respiration is C6 H12 O6 + 6O2 --> 6CO2 + 6H2O
Glucose is a 6-carbon molecule, and there is energy holding it together. Carbon dioxide is a 1-carbon molecule.
Glycolysis is process that turns the 6-carbon glucose into two 3-carbon pyruvate molecules. This process results in a little bit of usable energy (this energy is stored in the bonds of a molecule called ATP).
Between Glycolysis and the Kreb's Cycle, each of these 3-carbon pyruvate molecules becomes a 2-carbon molecule called Acetyl CoA. The 1-carbon is removed as a molecule of CO2, and some energy is released (this energy is stored in the bonds of a molecule called NADH)
The entire Kreb's cycle is just a way to convert each of the 2-carbon Acetyl CoA molecules into 1-carbon CO2 molecules, and the extra energy holding together the larger 2-carbon molecule is stored in the bonds of small molecules (the main one is called NADH).
In a way, you can think of Kreb's cycle as a catalyst for this simple breakdown of a 2-carbon molecule to a 1-carbon molecule (CO2). This process starts with a 4-carbon molecule (Oxaloacetate) binding to the 2-carbon molecule, and after the two CO2 + energy are released, it is left with the same 4-carbon molecule (Oxaloacatete)
The electron transport chain is a way to transfer the energy from the bonds of these small molecules (like NADH) into bonds of ATP molecules.
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ETC proteins are called cytochromes... there's reduction and oxidation as the electrons jump from the less electronegative molecule to the more electronegative one...till they reach oxygen, which is the most electronegative one, and which is also the final electron acceptor... as soon as it accepts the electrons, it becomes water...
no oxygen? you've got fermentation... 2 ATP's come out of it... with glycolysis, that's four ATPs...
although you get 2 ATPs from glycolysis, it's actually 4ATPs, but since you use 2 to get those 4, your NET product is 2 ATPs
what else...
the controversy between 36 vs. 38 ATP is based on ATP expenditure required to get into the mito...
no oxygen? you've got fermentation... 2 ATP's come out of it... with glycolysis, that's four ATPs...
although you get 2 ATPs from glycolysis, it's actually 4ATPs, but since you use 2 to get those 4, your NET product is 2 ATPs
what else...
the controversy between 36 vs. 38 ATP is based on ATP expenditure required to get into the mito...
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any of you know of any good interactive websites that demonstrate this?
I'd like to point out one error above.
Although some literature still uses 36-38 as the accepted values, it has since been shown and accepted in newer texts and even MCAT materials that the actual number of ATP produced is
30-32 ATP.
The reason is that it is 2.5 ATP produced per NADH and 1.5 ATP produced per FADH2 rather then 3 ATP produced by NADH and 2 ATP produced by FADH2.
Although some literature still uses 36-38 as the accepted values, it has since been shown and accepted in newer texts and even MCAT materials that the actual number of ATP produced is
30-32 ATP.
The reason is that it is 2.5 ATP produced per NADH and 1.5 ATP produced per FADH2 rather then 3 ATP produced by NADH and 2 ATP produced by FADH2.
