- What is the effect of sudden increase in the levels of ATP and citrate on an erythrocyte undergoing glycolysis?
(1) It inhibits glycolysis.
(2) It stimulates glycolysis.
(3) The rate of glycolysis remains unaltered.
(4) The rate of glycolysis increases gradually .
Role of ATP and Citrate in Cellular Energy Regulation
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ATP is the main energy currency of the cell. High levels of ATP indicate that the cell’s energy needs are met.
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Citrate is an intermediate of the citric acid cycle (Krebs cycle) and reflects the overall energy status and metabolic flux within the cell.
Both ATP and citrate serve as allosteric inhibitors of key glycolytic enzymes, signaling that energy production can be downregulated.
Key Regulatory Enzymes Affected
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Phosphofructokinase-1 (PFK-1):
The rate-limiting enzyme of glycolysis, which catalyzes the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate.-
ATP binds allosterically to PFK-1, inhibiting its activity when ATP levels are high.
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Citrate enhances this inhibition, further suppressing PFK-1 activity.
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Pyruvate Kinase:
Catalyzes the final step in glycolysis, converting phosphoenolpyruvate to pyruvate. ATP accumulation can inhibit this enzyme as well.
How ATP and Citrate Inhibit Glycolysis in Erythrocytes
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High ATP Levels:
When ATP accumulates, it signals that the cell’s energy demand is low. ATP binds to PFK-1, causing a conformational change that reduces enzyme activity, slowing glycolysis. -
High Citrate Levels:
Citrate, exported from mitochondria in cells that have them, accumulates in the cytosol and acts as a metabolic signal indicating sufficient energy and biosynthetic precursors.-
Citrate binds to PFK-1 and enhances ATP’s inhibitory effect.
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This dual inhibition ensures glycolysis is suppressed when energy and biosynthetic intermediates are abundant.
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Result:
The combined inhibitory effect of ATP and citrate decreases the rate of glycolysis, preventing unnecessary glucose breakdown and conserving resources.
Specific Considerations in Erythrocytes
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Although erythrocytes lack mitochondria and do not perform the citric acid cycle, citrate can still accumulate from other metabolic sources or be influenced by systemic metabolic states.
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The feedback inhibition by ATP and citrate ensures erythrocytes do not overproduce ATP when energy is sufficient, maintaining metabolic balance.
Summary Table: Effects of ATP and Citrate on Glycolysis
Molecule Effect on Glycolysis Mechanism ATP Inhibits glycolysis Allosteric inhibition of PFK-1 and pyruvate kinase Citrate Enhances ATP inhibition Allosteric inhibition of PFK-1 Result Decreased glycolytic rate Reduced conversion of glucose to pyruvate
Conclusion
A sudden increase in ATP and citrate levels in erythrocytes leads to inhibition of glycolysis through feedback regulation of key enzymes, primarily phosphofructokinase-1. This mechanism prevents excess ATP production when the cell’s energy needs are already met, ensuring efficient metabolic control.
Final Answer:
(1) It inhibits glycolysis. -
39 Comments
Kirti Agarwal
September 18, 2025It inhibits glycolysis
Aakansha sharma Sharma
September 19, 2025It inhibits glycolysis
Sonal Nagar
September 20, 2025inhibit glycolysis.
Khushi Agarwal
September 20, 2025Correct Answer
(1) It inhibits glycolysis.
ATP & Citrate = brakes for glycolysis.
Neha Yadav
September 20, 2025Sudden increase in ATP and citrate levels leads to inhibition in glycolysis
Bhawna Choudhary
September 20, 2025Inhibit glycolysis
Manisha choudhary
September 21, 2025suddenly erythrocyte m ATP and citrate ki concentration increase ho jaaye too glycolysis slowdown ho jayega
y allosteric inhibitor h jo regulation krwate h
ATP pFK-1 phosphofructokinase enzyme k active site p bind kr k conformation change kr dete h jis s fructose 6 p , fructose 1,6 bis p m convert nhi ho pata glycolysis inhibit ho jaate h citrate also binds with PFK and inhibit glycolysis
ATP also binds with pyruvate kinase and inhibit glycolysis
Phosphoenol pyruvate ko pyruvate m convert pyruvate kinse krta h
RBC k paas mitrochondria nhi hoti ,too krebs cycle bhi nhi hogi rbc
Citrate krebs cycle kaa intermediate h , citrate other metabolic reaction kaa product h jo accumulate hua h
Soniya Shekhawat
September 21, 2025Citrate and ATP serve as allosteric inhibitor for glycolytic enzyme and glycolysis when the ATP production level is high.
Minal Sethi
September 22, 2025ATP and citrate are allosteric inhibitors of glycolysis hence rise in their concentration inhibits glycolysis
Pallavi Ghangas
September 22, 2025hi concentration of ATP and citrate enabled glycolysis
Deepika sheoran
September 23, 2025Inhibit glycolysis
Roopal Sharma
September 23, 2025Citrate and atp inhibits the glycolysis
Heena Mahlawat
September 23, 2025Inhibits glycolysis
Dharmpal Swami
September 23, 2025Decrease glycolytic rate
Aafreen Khan
September 23, 2025It inhibits glycolytic enzyme phosphofructokinase
HIMANI FAUJDAR
September 23, 2025Ans Sudden Increase in ATP and Citrate can leads to decrease in the rate of glycolysis.
Both are allosteric inhibitors so ATP inhibits glycolysis and Citrate enhances ATP inhibition which reduced conversion of glucose to pyruvate.
Anurag Giri
September 23, 2025A sudden increase in ATP and citrate levels in erythrocytes leads to inhibition of glycolysis
Devika
September 23, 2025Inhibits glycolysis
Parul
September 23, 2025High level of ATP and Citrate in Erythrocytes inhibits Glycolysis.
Mohd juber Ali
September 24, 2025When ATp accumulate mean energy demand of cell low and reduce enzyme activity so glycolysis slow. ATP and citrate decreases the rate of glycolysis, preventing unnecessary glucose breakdown so option a right
Divya rani
September 24, 2025The ATP and citrate both work as allosteric enzyme or inhibitor so They both inhibits the glycolysis.
Nilofar Khan
September 24, 2025Correct answer is 1
Sudden Increase in ATP and Citrate can leads to decrease in the rate of glycolysis. So it inhibites glycolysis
Sakshi
September 24, 2025Sudden increase in ATP and citrate inhibit rate of glycolysis because ATP accumulates more so there is no need to form more ATP.
Aman Choudhary
September 24, 2025Option A is correct
Increase in ATP and citrate leads to inhibition of glycolysis
Kavita Choudhary
September 24, 2025Increase the level of ATP and citrate leads to inhibit the level of glycolysis
Santosh Saini
September 24, 2025ATP and citrate decrease the rate of glycolysis preventing unnecessary glucose breakdown. So it inhibit glycolysis
Khushi Singh
September 24, 2025High atp and citrate inhibits glycolysis
Arushi Saini
September 24, 2025Increased level ofATP as well as citrate inhibits glycolysis
Harish Kumar
September 25, 2025Inhibit glycolysis because bina necessary glycolysis nahi hoti h iske pass allready atp h
Payal Gaur
September 25, 2025Inhibit glycolysis because increased ATP in RBC so cell work slow requirements of glucose is decrease and citrate (mitochondria) not found in erythrocyte cell.
Sonam Saini
September 25, 2025High Atp and citrate inhibit tha glycolysis is right answer
Avni
September 25, 2025The combined inhibitory effect of ATP and citrate decreases the rate of glycolysis
Priya dhakad
September 25, 2025Sudden Increase in ATP and Citrate can leads to decrease in the rate of glycolysis.
Both are allosteric inhibitors ,so ATP inhibits glycolysis and Citrate enhances ATP inhibition which reduced conversion of glucose to pyruvate.
Muskan Yadav
September 26, 2025A sudden increase in ATP and citrate levels in erythrocytes leads to inhibition of glycolysis through feedback regulation of key enzymes, primarily phosphofructokinase-1.
Bhavana kankhedia
September 29, 2025It inhibits glycolysis.
karishma don
October 1, 2025excess ATP accucmulation singals the body that slow down glycolysis, iss human ke pass atp kaafi hai, she doesn’t require much energy. aur joh accumulated atp ibins tp pFK and inhibits the activity of phospofructokinase and citrate too is an inhibitor leads in decrease of glycolysis
Kajal
October 3, 2025Both inhibit glycolysis
sakshi khatri
October 18, 2025inhibit glycolysis
Sakshi Kanwar
November 25, 2025inhibition of glycolysis as ATP binds allosterically to PFK-1