Molecules derived from the breakdown of fats, proteins, and carbohydrates can enter glycolysis or the Krebs cycle at various points in order to yield more energy to an organism. Part A How does oxygen get into or out of chloro- plasts and mitochondria? Part B What are the roles of oxygen in the processes of photosynthesis and cellular respiration, and how are the roles similar? Make sure you get plenty of rest the night before the test
Cellular Respiration
Remember that for each molecule of glucose, two Acetyl Co-A molecules are produced; therefore the KCAC occurs twice for each glucose, so all products here are X 2.
With anaerobic respiration the shortage of oxygen in the cells means that they must find another way to convert NADH back into NAD, this process is called fermentation. Electron Transport Chain The third stage consists mainly of the movement of H+, carried by NADH2, from the matrix into the intermembrane space via proton pumps in the mitochondria
Amino Acids Are Made from Intermediates of the Citric Acid Cycle and Other Major Pathways - Biochemistry - NCBI Bookshelf
An Adenylated Intermediate Is Required to Form Asparagine from AspartateThe formation of asparagine from aspartate is chemically analogous to the formation of glutamine from glutamate. Methyl groups enter the cycle in the conversion of homocysteine into methionine and are then made highly reactive by the addition of adenosyl groups, which make the sulfur atoms positively charged and the methyl groups much more electrophilic
I really appreciate this explanation, many thanks Reply jake says: May 8, 2011 at 23:30 Great review before my AP bio test, many thanks! Reply Ikpoku Justice says: March 25, 2011 at 08:37 i appreciate your site and how its making science easy. Reply Rob says: November 20, 2010 at 18:30 dear admin, i dont know if this comment site is also designed for questions, but as a lay person trying to understand a metabolic condition my 10 yr old son has, i found your description of the krebs cycle easy to follow
Krebs Cycle - Biology Encyclopedia - cells, body, process, system, used, membrane, molecules, energy
As the reactions of the Krebs cycle continue, the two acetyl carbons are successively oxidized to carbon dioxide, forming two molecules of NADH and one of FADH 2 , which will provide electrons to the electron transport chain to form ATP. At this point, two of the original three carbon atoms in pyruvate have been incorporated into citric acid and one has been oxidized to carbon dioxide, and one molecule of NADH has been produced
doc3232 Joined: 02.15.08 Messages: 3,811 Status: Dental Student Not to confuse even more, but some books say only 2.5 ATP are made from NADH and 1.5 ATP from FADH2...I think Princeton does this. Andre3k Joined: 07.14.08 Messages: 283 Location: Columbus, Ohio Status: Dentist 4 ATP substrate level 32 ATP electron transport chain In prokaryotes the NADH from glycolysis dont have to cross a mitochondrial membrane so you get all the ATP youre supposed to get for them
Krebs Cycle - Biology Video by Brightstorm
The Krebs cycle takes in those pyruvates breaks it up spits out a little bit more ATP and then sends off the NADH and FADH2 which are high energy electron carriers off to electron transport system. But in general what happens is that pyruvate from glycolysis out in the cytoplasm as it starts to enter into the mitochondria enzymes will rip off a couple of high energy electrons and put them onto an electron carrier called NAD positive
In this case, carbon dioxide gets used to produce sugars in a series of reactions called the Calvin Cycle, C4 photosynthesis, and crassulacean acid metabolism. There are a couple of ways this works in cells: -glycolysis, in which glucose is broken up into two subunits, called pyruvate, which creates two units of ATP per molecule of glucose
Krebs Cycle - Chemistry Encyclopedia - reaction, water, proteins, coenzymes, molecule
Many types of fuel molecules can be drawn into and utilized by the cycle, including acetyl coenzyme A (acetyl CoA), derived from glycolysis or fatty acid oxidation . The sequence of events known as the Krebs cycle is indeed a cycle; oxaloacetate is both the first reactant and the final product of the metabolic pathway (creating a loop)
The phosphoryl group in GTP is then transferred to adenosine diphosphate (ADP) to form ATP, in a reaction catalyzed by the enzyme nucleoside diphosphokinase. However, this problem is overcome in the first step of the Krebs cycle when the acetic acid of acetyl-CoA is combined with oxaloacetate to yield citrate, which is much more susceptible than the acetyl group to the dehydrogenation and decarboxylation reactions needed to remove electrons for reduction of NAD+ and FAD+
It is present in the cytoplasm and nucleoplasm of every cell, and essentially all the physiological mechanisms that require energy for operation obtain it directly from the stored ATP. For animals, you use the energy from your high energy storage molecules to do what you need to do to keep yourself alive, and then you "recharge" them to put them back in the high energy state
If antioxidant and conjugation steps are impaired, then a large number of free radicals will be produced which can cause oxidative damage within the liver and also spill out into the blood stream, flooding it with excessive free radicals. In addition, poor immune function may result in cytokines attaching themselves to the mitochondrial membrane, and perhaps causing mitochondrial clumping (which in turn may disturb the function of the cytoskeleton within the cytoplasm of the cells)
Glycolysis
An eight-carbon fatty acid can produce 4 acetyl CoA's Each acetyl CoA is worth 12 ATP's (3 NADP, 1 FADH2, 1 ATP) Therefore, this short fatty acid is worth 48 ATP's, a fat with three chains of this length would be worth 144 ATP's! This is why fats are such a good source of energy, and are hard to lose if you want to lose weight A comparison between Plants and Animals Animal cells and Plant cells contain mitochondria! However, animal cells contain many more mitochondria than plant cells Animal cells get most of their ATP from mitochondria Plant cells get most of their ATP from the chloroplast The ATP generated from the mitochondria is only used when the plant cannot generate ATP directly from the light-dependent reactions Other Uses for Molecules used in Glycolysis and the Krebs Cycle Not all of the molecules that enter Glycolysis and the Krebs Cycle are used for energy Some are used to synthesize fats, nucleotides, amino acids, and other biologically important molecules
Glycolysis, Krebs Cycle, andother Energy-Releasing Pathways
An eight-carbon fatty acid can produce 4 acetyl CoA's Each acetyl CoA is worth 12 ATP's (3 NADP, 1 FADH2, 1 ATP) Therefore, this short fatty acid is worth 48 ATP's, a fat with three chains of this length would be worth 144 ATP's! This is why fats are such a good source of energy, and are bad if you want to lose weight A comparison between Plants and Animals Animal cells and Plant cells contain mitochondria! However, animal cells contain many more mitochondria than plant cells Animal cells get most of their ATP from mitochondria Plant cells get most of their ATP from the chloroplast The ATP generated from the mitochondria is only used when the plant cannot generate ATP directly from the light-dependent reactions
How Much ATP Is Produced In The Krebs Cycle Alone? - Naked Science Forum
This is partly because the subsystems are not isolated but interact and largely because all living entities, not least cells, are highly autodynamic because the relevant control reactions operate in their oscillatory mode. Unfortunately most cell scientists ignore this reality with the consequence that many of their experimental results are open to question and they are unable to provide answers for major problems
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