Keep On Running

Energy For all of Us

• Cellular activity– Large molecules cannot be used by the

cells for energy (muscles, etc)

– Molecules must be broken down into a form that the cells can use

– ATP is commonly used in organisms as a direct source of energy.

Adenosine triphosphate (ATP)

• The energy currency or coin of the cell– Lots of $100 bills break down into $10 bills

• Carriers or transfers useful amounts of energy to other molecules in the cell so other reactions can occur.– Rechargeable battery of the cell– ATP is the high energy form (the

recharged battery)

Cellular Respiration

• Process by which enzymes convert the energy stored in macromolecule (starch) or small molecule (glucose) into the useable form of ATP

• 3 stages– Glycolysis– Krebs Cycle– Electron Transport System

Stages Defined• Stage 1 Glycolysis

– Occurs in Cytoplasm– Splits glucose into two smaller molecules,

and producing small amounts of ATP

• Stage 2 Krebs Cycle (aerobic respiration)

– Occurs in Mitochondria– Enzymes breakdown two small molecules

into CO2 and several ATP molecules

– CO2 expelled during breathing

Stages Continued• Stage 3 Electron Transport System

– Occurs in Mitochondria

– After ATP is captured remaining energy is in form of hydrogen atoms.

– Carrier molecules transport to this last stage

– Transferred to ATP by removing electrons to create (H+) and (e-)

Stage 3 Continued

– Electrons transferred to carrier molecules.

• Relay across the mitochondria releasing small amounts of energy.

• Protons diffusion process converts energy into many ATP molecules.

– Electrons and Protons combine with (O2) to form water (H2O)

End of Processes

• Cellular Respiration’s end is many ATP molecules from all 3 stages

• Smaller molecules from glycolysis

• CO2 from Kreb’s cycle

• H2O from Electron transport system