(7)	Cellular+respiration+–+The+process+(this+is+your+most+difficult+topic+–+put+good+students+on+it)

=Cellular Respiration=







//**Why do we digest food? **//

Food is digested because it needs to be broken down in order for it's nutrients to be absorbed into the bloodstream.

//**Where does cellular respiration occur? **//

Cellular respiration occurs in the mitochondria.  media type="youtube" key="-XGrtSA6BOs" height="315" width="560" align="center"

//**What does it need? **//

Cellular respiration needs oxygen to turn glucose into carbon dioxide and enzymes to break down the food.

//**What does it produce? **//

It produces temporary carrier proteins that charge ATP particles.

//**What are the four steps? Describe key event in each. **//


 * 1)  Glycolysis - this is where the glucose molecule is broken down into 2 sets of 3 carbon particles.
 * 2) Link reaction - this is when the carbon is broken down into more pieces and one set of three becomes two sets, one consisting of 2 carbon molecules and the other of one CO2 molecule. The carbon turns into CO2 because it joins up with two oxygen particles.
 * 3) Krebs Cycle - this is when the 2 carbon molecules left over are grouped with the 4 carbon molecules to make a group of 6 molecules (but rearranged in comparison to when it was a glucose molecule), they are broken down bit by bit and the broken down parts are temporary energy carriers and the process is repeated after every 2 carbon particles are turned into carrier proteins and the remaining 4 molecules rejoin with another pair of carbon molecules.
 * 4) Electron transport chain - when the temporary carrier proteins produced charges up ATP particles.

//**How much energy is produced with O2 (and without O2)? **//

4 ATP particles are charged up in total; half of them are produced with O2 during the link reaction phase and the other half without O2 per each Krebs cycle.

//**<span style="font-family: Tahoma,Geneva,sans-serif;">Why the difference? **//

<span style="font-family: Tahoma,Geneva,sans-serif;">O2 is required during the link reaction because the remaining carbon particle requires O2 in order to be broken apart from the other 2 carbon particles.

For more clarification, watch this awesome version of I Gotta Feeling: Cellular Respiration Edition!

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