Photosynthesis #6: BIO 1A (editing)

what cellular activities require energy?

• metabolizing (‘breaking down’ molecules)

• synthesizing (‘buildin’) molecules

• fighting pathogens

• exporting wastes

• cell division & growth

• reproduction

Process of breaking down carbon based food

animals: digest food first

plants: create food in simple form (glucose) - no need for digestion

energy extracted form food molecules through cellular respiration (occurs in mitochondria)

Energy transformation

plants transform solar energy into chemical energy stored within organic molecules (photosynthate)

sunlight (solar energy): 6CO2 (carbon dioxide) + 6HH2O (water) → C6H12O6 (glucose) + O2 (oxygen)

chemical energy (atp)

energy available in molecules that is released in a chemical reaction

• chemical energy (potential energy) in amylose (polysaccharide in starch) due to structure of amylose molecules

ATP (adenosine triphosphate)

immediate energy source that fuels all activities of all organisms

• potential chemical energy isstored in chemical bonds in ATP

• - fuels all cell activities

Where are ATP molecuels stored?

In phosphate bonds

• adding phosphate group to ATP required alrge amount of energy, created high-energy chemical bonds

• breaks high-energy phosphate bond, releases energy

• ATP is a fragile molecule

What is ATP ‘used” to break?

used by breaking a high-energy bond to release energy

• breaking phosphate bond changes ADP to ATP

• Energy released is used by cell to do ‘work’