University:
Michigan State University
Course:
BS 161 | Cell and Molecular Biology
Academic year:

2022
Views:

388

Pages:

7
Author:

Hallie Randolph

WHAT IS ATP-AD CYCLE? The ATP-ADP cycle is a fundamental process that occurs in cells to provide energy for various biological functions. Here's how it works: ATP (ADENOSINE TRIPHOSPHATE) IS THE ENERGY CURRENCY OF THE CELL. IT CONSISTS OF THREE PHOSPHATE GROUPS, A RIBOSE SUGAR, AND AN ADENINE BASE. THE BONDS BETWEEN THE PHOSPHATE GROUPS STORE A SIGNIFICANT AMOUNT OF ENERGY. WHEN A CELL NEEDS ENERGY FOR PROCESSES SUCH AS MUSCLE CONTRACTION, ACTIVE TRANSPORT, OR BIOSYNTHESIS, ATP BREAKS DOWN INTO ADP (ADENOSINE DIPHOSPHATE) AND A FREE PHOSPHATE GROUP (Pᵢ). THIS REACTION RELEASES ENERGY, WHICH THE CELL CAN USE. THIS PROCESS IS CALLED HYDROLYSIS OF ATP. ATP → ADP + Pᵢ + ENERGY ONCE ADP IS FORMED, IT CAN BE RECYCLED BACK INTO ATP. THIS REQUIRES ENERGY, WHICH IS TYPICALLY DERIVED FROM THE BREAKDOWN OF NUTRIENTS SUCH AS GLUCOSE DURING CELLULAR RESPIRATION. IN THE MITOCHONDRIA, ADP IS CONVERTED BACK INTO ATP BY ADDING A PHOSPHATE GROUP. THIS PROCESS IS CALLED PHOSPHORYLATION, AND IT OCCURS MAINLY DURING OXIDATIVE PHOSPHORYLATION IN THE PRESENCE OF OXYGEN. ADP + Pᵢ + ENERGY → ATP The cycle is continuous: ATP is consumed for energy, converted to ADP, and then recharged back into ATP, providing a renewable energy source for cells. THANK YOU