C1.2.1— ATP as the molecule that distributes energy within cells.

Structure of ATP:

• ATP stands for Adenosine TriPhosphate
• Adenosine is a hexagon and a pentagon (ADENINE) attached to a bigger pentagon (RIBOSE)
• Which is then attached to three phosphate groups
• The bonds between all the phosphate groups are HIGH ENERGY BONDS - Chemical bonds that store a high amount of energy
• NOTE: The only difference between ATP and ADP is that ATP is Triphosphate (so three phosphates) and ADP is Diphosphate (Two phosphates)

Why is ATP a good Energy Currency?

• High-energy phosphate bonds
• Phosphoryl transfer capability - Can activate or deactivate specific proteins, enzymes, and molecules, helping regulate cellular processes
• Rapid energy release upon hydrolysis
• Efficient recycling from ADP and Pi (Inorganic Phosphate) - Can be made from ADP and Pi through a process called oxidative phosphorylation, which uses oxygen during respiration, keeping a constant ATP supply in the body
• Versatile involvement in various cellular reactions

C1.2.2— Life processes within cells that ATP supplies with energy.

• Active transport across membranes, cell division, protein synthesis, photosynthesis, and muscle contraction.

1. Active Transport: ATP powers active transport processes that move ions or molecules against their concentration gradients across cell membranes. Examples include the sodium-potassium pump, which maintains ion balance in nerve cells.
2. Cellular Respiration: The production of ATP through cellular respiration involves multiple steps, including glycolysis, the citric acid cycle, and oxidative phosphorylation. ATP is generated as a result of the breakdown of glucose and other energy-rich molecules.
3. Protein Synthesis: Both transcription and translation, key steps in protein synthesis, require ATP. Transcription converts DNA into RNA, while translation uses ATP to assemble amino acids into polypeptide chains.