Here is just my logic (but someone else will explain better):
- without oxygen, NADH can't be converted back to NAD in ETC. So there is no NAD for Krebs cycle
- ATP has to be used to make more ATP, so if 32 net ATP isn't produced in ETC (as a result of no oxygen present), then there is less ATP to carry out specific reactions (such as Krebs Cycle)
Hopefully that's right.
Ok, so the order of the reactions is:
-Glycolysis
-Kreb's Cycle
-Electron Transport Chain
In Glycolysis, we don't need oxygen. However, for the pyruvates to move into the mitochondria, the presence of oxygen is required. So, even though the later 2 reactions might not directly need oxygen, the cell needs to have oxygen for the reactions to continue.
Hopefully that makes sense.
How can Homo Neanderthalensis and Homo Erectus interbreed if they are separate species? Is this an exception to the rule...
hmmm... my guess is that these species can only interbreed to produce infertile offspring? I know that this happens with mules, not sure if the same applies to humans
However, if this above assumption is indeed correct, it would not be 'an exception the rule' provided that the offspring are
infertile, meaning they themselves cannot reproduce.
Not sure about this though.