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From Biolk483
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**-11.3 kcal | **-11.3 kcal | ||
**Seen in prokaryotes | **Seen in prokaryotes | ||
| - | * | + | *Phosphocreatine |
**-10.3 kcal | **-10.3 kcal | ||
**This is a storage form of high energy phosphate. | **This is a storage form of high energy phosphate. | ||
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<h2>Low energy phosphates</h2> | <h2>Low energy phosphates</h2> | ||
| - | * | + | *AMP -> Adenosine + Pi |
**-3.4 kcal | **-3.4 kcal | ||
*Sugar phosphates | *Sugar phosphates | ||
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***This charge should range form 0.8 to 0.95. | ***This charge should range form 0.8 to 0.95. | ||
| - | ===End of Second Exam | + | ===End of Second Exam Material=== |
Current revision as of 16:26, 9 November 2009
- Exam II is multiple choice.
Contents |
ATP (continued)
The energy of ATP
- Why do we lose -7.3 kcal of energy when we cleave off 1 Pi? Three reasons.
- Resonance
- There are 4 possible resonance structures when in ATP form.
- There are 5 possible resonance structures when in ADP + Pi form.
- Release of charge stress
- Net charge on ATP is -3.5
- Net charge on ADP + Pi is -4, so although there is more charge, it is separated on two separate molecules.
- Net Hydration
- We can get more H2O around ADP and Pi than just around ATP. Since ATP and ADP and Pi are polar, they like having lots of H2O around them.
- These 3 reasons explain why there is such a high dG available from ATP.
- Resonance
High Energy Compounds
- PEP
- -14.8 kcal
- The most energetic
- Anything can phosphorylate things below it in this chart
- Carbonyl phosphate
- -12.3 kcal
- Seen in urea cycle
- 1,3 Diphosphoglycerate
- -11.8 kcal
- Found in glycolosis
- Acetyl phosphate
- -11.3 kcal
- Seen in prokaryotes
- Phosphocreatine
- -10.3 kcal
- This is a storage form of high energy phosphate.
- It has a phosphoramidate bond.
- ATP -> AMP + PPi
- -10 kcal
- ATP -> ADP + Pi
- -7.3 kcal
- ADP -> AMP + Pi
- -7.3 kcal
Low energy phosphates
- AMP -> Adenosine + Pi
- -3.4 kcal
- Sugar phosphates
- -5 through -2 kcal
- Put the Pi on sugar from ATP to make these low energy holding molecules.
- We start glycolosis by making one of these sugars.
Example of Pi Movement
- PEP + ADP -> Pyruvate + ATP, then ATP + glucose ---via hexokinase---> glucose 6 phosphate
- Storage forms: phospho creatine, phophoargine, polymetaphosphate (primitive)
Bioenergetics in vivo
- In a cell, the concentration of ATP is far greater than the concentrations of ADP and Pi
- If this is not the case, it is often because of age or disease
- Energy Charge: the ratio of ATP to ADP+Pi.
- If the energy charge is 1, then there is 100% ATP, if 0, all ADP + Pi.
- 0.8 might be observable in a very run down, in poor health individual. Very near death.
- The charge is calculated as (0.5[ADP] + [ATP]) / ([AMP] + [ADP] + [ATP])
- This charge should range form 0.8 to 0.95.
