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22 Cards in this Set
- Front
- Back
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Regulation metabolic pathways
Regulation is required because.. |
of the shifting demands in the human due to different physiological situations.
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Regulation metabolic pathways:
the shift in demand for energy (ATP) can increase > 100-fold due to? |
exercise.
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Regulation metabolic pathways
Changes in diet (eg., starvation) would cause shifting from? |
one pathway to another.
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Regulation of metabolic pathways:
Regulation is required because the shifting demands due to different physiological situations How is this done? i.e., what mechanism do cells utilize to maintain homeostasis? |
It is important to know that despite variances in diet in quantity and quality living cells maintain a dynamic steady state.
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Regulation of metabolic pathways
the substrate in each metabolic pathway is provided by ...? |
the preceding reaction at the same rate it is consumed.
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Regulation of metabolic pathways
The flux in the pathways during regulation may be at any rate but the concentration of S ... Thus, v1 v2 A -------> S ----------> P and v1 = v2 therefore S =? |
- does not change.
- constant. |
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Regulation of metabolic pathways
If the steady state is changed then altered fluxes cause .... |
regulatory mechanisms to become operative.
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Regulation of metabolic pathways
An important function of the cell is to maintain a ......... since any change in ATP supply would effect many pathways. |
constant [ATP] concentration
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Regulation of metabolic pathways
a ____________ mechanism has been developed to maintain the ATP concentration. |
regulatory
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Regulation of metabolic pathways
When ATP is utilized it is converted to ? |
ADP or AMP
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Regulation of metabolic pathways
ADP is in equilibrium with .... via the Adenylate kinase reaction. |
AMP and ATP
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Regulation of metabolic pathways
ADP is in equilibrium with AMP and ATP via ? |
the Adenylate kinase reaction
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Regulation of metabolic pathways
2 ADP <=====> ???????? |
ATP + AMP
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Regulation of metabolic pathways
some regulatory reactions are affected by the ???? ratio. |
[ATP]/[AMP]
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Regulation of metabolic pathways
It turns out that AMP is .............. of the energy state of the cell. |
a more sensitive indicator
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Regulation of metabolic pathways
It turns out that AMP is a more sensitive indicator of the energy state of the cell. This is due to.. |
the fact that ATP is high (~5 to 10 mM) compared to AMP (~0.1 mM).
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Regulation of metabolic pathways
If 10% of the ATP is used in a reaction there are bigger changes in the AMP concentration due to... |
the adenylate kinase reaction.
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Regulation of metabolic pathways
a 10% decrease in ATP there is a .........in AMP. |
6-fold or 600% increase
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Regulation of metabolic pathways
the cell many regulatory processes are affected by ??? |
[AMP].
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Regulation of metabolic pathways
4 Regulatory processes that are present in the cell |
1. Maximize fuel utilization efficiency by preventing simultaneous operation of pathways in opposite directions. (eg., gluconeogenesis and glycolysis).
2. Partition of metabolites between alternative pathways such as glycolysis and pentose-P pathway. 3. Utilizing the fuel best suited for the needs of the organism. 4. Regulation of biosynthetic pathways when their end products accumulate. |
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Regulation of metabolic pathways
Usually the regulatory enzyme is never at its equilibrium as it is a rate limiting reaction compared to other enzymes in the cell. Because of the prevailing concentrations of substrates and effector molecules. Regulatory enzymes are thus, |
exergonic.
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Regulation of metabolic pathways
Steps 2 and 3 in regulatory pathways are ...... while step 1 is ....... in steady state |
- at equilibrium
-not when the pathway is |
