How does ATP typically transfer energy from an exergonic to an endergonic reaction in the cell?

Short Answer

Expert verified

ATP transfers a phosphate group to the reacting molecule of the endergonic reaction. The energy from the phosphate group drives the endergonic process. This way, ATP transfers energy from an exergonic to an endergonic reaction.

Step by step solution

01

Structure of ATP molecule

ATP (adenosine triphosphate) consists of a ribose sugar, an adenine base, and three phosphate groups. The three phosphate groups are attached through phosphoanhydride bonds.

ATP hydrolysis involves the breaking of a phosphoanhydride bond that removes a phosphate group releasing free energy. As a result of ATP hydrolysis, ADP (adenosine diphosphate) and Pi (inorganic phosphate) are produced.

02

ATP couples exergonic and endergonic reactions

The exergonic reaction releases energy, whereas the endergonic reaction absorbs energy. Thus, exergonic reactions are coupled to endergonic reactions. This is because endergonic reactions use the energy released by exergonic reactions.

The cells in the body couple exergonic and endergonic reactions using ATP hydrolysis because the energy released during ATP hydrolysis drives unfavorable reactions in the cell.

03

Phosphorylation of reactant molecule drives the endergonic reaction

ATP involves phosphorylation, where the Pi released on ATP hydrolysis is transferred to a reactant molecule. The phosphate group covalently binds to the reactant molecule and is called phosphorylated intermediate.

The phosphorylated molecule has a higher energy level than its unphosphorylated form. This additional energy drives the endergonic reaction. Thus, ATP transfers energy from exergonic to endergonic reactions in the form of phosphorylation.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Question: If an enzyme is added to a solution where its substrate and product are in equilibrium, what will occur?

  1. Additional substrate will be formed.
  2. The reaction will change from endergonic to exergonic.
  3. The free energy of the system will change.
  4. Nothing; the reaction will stay at equilibrium.

Some nighttime partygoers wear glow-in-the-dark necklaces. The necklaces start glowing once they are “activated” by snapping the necklace in a way that allows two chemicals to react and emit light in the form of chemiluminescence. Is the chemical reaction exergonic or endergonic? Explain your answer.

Question: Life requires energy. In a short essay (100-150 words), describe the basic principles of bioenergetics in an animal cell. How is the flow and transformation of energy different in a photosynthesizing cell? Include the role of ATP and enzymes in your discussion.

Question: A researcher has developed an assay to measure the activity of an enzyme present in pancreatic cells growing in culture. She adds the enzyme’s substrate to a dish of cells and then measures the appearance of reaction products. The results are graphed as the amount of product on the y-axis versus time on the x-axis. The researcher notes four sections of the graph. For a short period of time, no products appear (section A). Then (section B) the reaction rate is quite high (the slope of the line is steep). Next, the reaction gradually slows down (section C). Finally, the graph line becomes flat (section D). Draw and label the graph, and propose a model to explain the molecular events occurring at each stage of this reaction profile.

Question: If an enzyme in solution is saturated with substrate, the most effective way to obtain a faster yield of products is to

  1. add more of the enzyme
  2. heat the solution to 90°C.
  3. add more substrate
  4. add a non-competitive inhibitor
See all solutions

Recommended explanations on Biology Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free