5.7.1 - the need for cellular respiration

• Why do organisms need to respire?

  • respiration occurs in living cells and releases the energy stored in organic matter.
  • the energy is used to synthesis molecules of ATP from ADP and inorganic phosphate
  • ATP in cells can be hydrolysed to release energy to drive biological processes
  • microorganisms all respire to obtain energy
• why do organisms need energy?

  • when energy is released from organic molecules, via respiration, it cam be used to make ATP to drive biological processes such as:
  • endocytosis
  • protein synthesis
  • active transport
  • Metabolic reactions (anabolic & catabolic)
  • cell organelle movement
  • cell division
  • DNA replication
• learning tip --- respiration releases energy from respiratory substance such as glucose, but some of it reeaswed energy can be used ti make ATP
• what is ATP?

  the standard intermediate between energy -releasing and energy-consuming metabolic reactions in both prokaryotic and eukaryotic cells
• • Structure of ATP:
  • Adenosine (nitrogenous base adenine)
  • 5 carbon sugar ribose
  • 3 phosphate (phosphoryl) groups
• Describe the role of ATP synthase in the formation and breakdown of ATP

  • ATP is the immediate energy source for this metabolic reaction.
  • when ATP is hydrolysed to ADP + P1, a small amount of energy is released for use in cells. Cells can therefore obtain the energy they need for process in small amounts that not cause damage/waste.
• why is ATP the universal energy currency?

  • occurs in all living cells
  • is a source of energy that can be used by cells in small amounts.