Could someone please explain cellular respiration in the easiest terms possible?
All the arrows in the diagrams and the values of the inputs and outputs are really confusing me 
Much appreciated 
This topic felt so much easier when things were kept simple, so I'll try outline what I gathered from it all (:
Cellular Respiration can be of two types: Anaerobic or Aerobic.
Anaerobic respiration occurs in the absence of oxygen, whereas Aerobic respiration requires the presence of oxygen.
In glycolysis, 1 molecule of glucose is split into 2 molecules of pyruvate in the cytosol. This process requires 2 ATP, but yields 4 ATP (hence the net yield is 2ATP). NAD is loaded to NADH for each molecule of pyruvate (so you actually end up getting 2 NAD being loaded to 2NADH). Glycolysis is required for both anaerobic and aerobic respiration.
In Anaerobic respiration, the carrier molecules (NADH from glycolysis) are used to produce 2Ethanol & 2CO2 molecules in plants or lactic acid (2 molecules of lactate) in animals. Note that the two pyruvates which were produced in glycolysis are considered the inputs in this stage. Anaerobic respiration itself does not yield any ATP, although the 2ATP netted in glycolysis should be considered.
Aerobic respiration occurs in the matrix of mitochondria, and is coupled to the electron transport chain (which occurs in the cristae of mitochondria). After glycolysis has occurred, a 'link reaction' takes place to form an intermediate product (2C) that combines with a 4C compound (or 'respiratory substrate') to enter the Kreb's cycle. The Kreb's cycle removes carbon from this 6C compound (or 'respiratory substrate') in stages, which is let out as carbon dioxide. One 2C has been removed as carbon dioxide (meaning the substrate is now 4C) it combines with the 2C intermediate product at the start of the cycle, allowing the cycle to start all over again! During the Kreb's cycle certain electron carriers (NAD and FAD) are loaded with Hydrogen to form NADH and FADH
2, and there is a net yield of 2ATP as well.
In the electron transport chain, these carriers unload their Hydrogen ions. The Hydrogen ions flow through a pump(s) in the cristae producing energy in the form of ATP. This produces 32 or 34 ATP.
I'm not going to write out the whole equation as that's kinda pointless I think, but know that it was formed by just adding all the reactants of the process on one side and the net yields of all the products on the other side.
That's basically it. I've skipped over lot of the technical speak as books contain so much of it already. I've also skipped lots of numbers and amounts of stuff, but unfortunately this is something you've probably got to memorise.
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