AP BIOLOGY

Detailed explanation-1: -The energy used to obtain, transfer, and transport materials within an organism comes directly from ATP. Adenosine triphosphate (ATP) is a nucleoside triphosphate, a small molecule used in cells as a coenzyme. It transports chemical energy in cells.

Detailed explanation-2: -The chemical energy that organisms need comes from food. Food consists of organic molecules that store energy in their chemical bonds.

Detailed explanation-3: -Through metabolic processes, ATP becomes hydrolyzed into ADP, or further to AMP, and free inorganic phosphate groups. The process of ATP hydrolysis to ADP is energetically favorable, yielding Gibbs-free energy of-7.3 cal/mol.

Detailed explanation-4: -ATP is able to power cellular processes by transferring a phosphate group to another molecule (a process called phosphorylation). This transfer is carried out by special enzymes that couple the release of energy from ATP to cellular activities that require energy.

Detailed explanation-5: -In general, the main energy source for cellular metabolism is glucose, which is catabolized in the three subsequent processes-glycolysis, tricarboxylic acid cycle (TCA or Krebs cycle), and finally oxidative phosphorylation-to produce ATP.