Adenosine Triphosphate (ATP)

Overview

• ATP Definition: Energy-carrying molecule found in the cells of all living things.
• Role: Captures chemical energy from the breakdown of food molecules and releases it to fuel other cellular processes.
• Energy Uses in Cells:
  • Drives metabolic reactions.
  • Transports substances across membranes.
  • Performs mechanical work (e.g., muscle movement).

Structure of ATP

• Components:
  • Nitrogenous base: Adenine.
  • Sugar: Ribose.
  • Three phosphate groups.
• Energy Source: Energy is contained in the bonds between phosphate groups.
• Hydrolysis: Addition of a water molecule breaks these bonds, releasing energy.
  • Converts ATP to adenosine diphosphate (ADP) when one phosphate is removed.

Function of ATP

• Energy Shuttle: Transfers energy to locations in the cell where energy-consuming activities occur.
• Phosphorylation: Transfer of a phosphate group to another molecule, powering cellular processes.
• ATP Regeneration: Constantly synthesized from ADP and phosphate via cellular respiration.

ATP Production

• Processes:
  • Glycolysis.
  • Tricarboxylic acid cycle (TCA cycle).
  • Oxidative phosphorylation.
• Location: Occurs in mitochondria in eukaryotic cells.
• ATP Synthase: Enzyme that facilitates the conversion of ADP and phosphate to ATP.
  • Located in mitochondria and chloroplasts in plant cells.

Metabolism and ATP

• Role in Metabolism: Central to energy metabolism, discovered by Fritz Albert Lipmann and Herman Kalckar in 1941.
• Metabolic Reactions:
  • Catabolism and anabolism, integration of energy exchanges.
  • Biological energy transduction.

Key People

• Contributors:
  • John Walker.
  • Jens C. Skou.
  • Paul D. Boyer.

Additional Information

• Related Processes:
  • Cellular respiration.
  • Photosynthesis.
  • Glycolysis.

Note: ATP is crucial for maintaining biological functions and facilitating energy transfer necessary for life processes.