Explaining Dragons: aerobic vs. anaerobic

Monday, February 8, 2016

Biology Example Question #1 Distinguish between aerobic and anaerobic respiration

This is going to be the first post in a series of posts which answers (often short hand) several biology questions, that do well to summarize large sections of a high school level course. Again please be aware that I am no scientist, so take my words with a pinch of salt. Also, I won't be writing these rambling sort of introductions for the next posts, so there's that. Now on to the answer.

Thank you again to my biology teacher for teaching me everything I know about this!

Labelled for reuse https://upload.wikimedia.org/wikipedia/commons/b/b9/Human_smoke_rings.jpg

Cellular respiration is the process whereby glucose is converted into usable energy, in the form of ATP. The amount of ATP produced depends on the whether or not oxygen is present. If oxygen is present aerobic respiration is undertaken, if not then anaerobic respiration is undergone. In aerobic respiration a total of 36 ATP molecules are produced, whereas in aerobic respiration only 2 ATP molecules are produced.

Both processes begin in the cytoplasm of a cell, however, aerobic respiration will continue in the matrix and inner membranes of the mitochondria. Whilst anaerobic respiration only undergoes glycolysis aerobic respiration will also involve the link reaction, the krebs cycle, and the electron transport chain. Aerobic respiration will result in 10 NADH molecules and 2 molecules of FDH2 (electron carriers) whilst anaerobic respiration will only result in 2 NADH molecules.

Both processes undergo glycolysis resulting in two pyruvate molecules, however whilst in aerobic respiration they go on to be modified in the link reaction and so forth, in anaerobic respiration other bi products are formed with no additional ATP formed.

If anaerobic respiration takes place in a yeast cell ethanol and CO2 will be the bi-products, whilst in humans the bi-product is lactate (also known as lactic acid).

I hope this was edumactional. I realize that is not a word.

Saturday, May 30, 2015

yeast

Aerobic vs. Anaerobic Respiration (I realize you probably don't care)

Hakuna Matata 3:07 PM

Labeled for resuse link

Hello again. Back to the world of biology. Whether or not that pleases you, I don't know. Anywho. My last post introduced you to the fine-art of glycolysis. If you still don't understand it, well, reread the blogpost? Otherwise Khan Academy is pretty darn amazing.

Anyway. As I said earlier glycolysis occurs in both aneorobic and aerobic respiration. I should probably clarify that with aneorobic respiration there is no available oxygen, with aerobic respiration there is. So as we all now know, the products of glycolysis are: 2 pyruvate molecules, 4 ATP (for a net gain of 2), and 2NADH molecules.

In aerobic respiration the two pyruvate molecules and the NADH will proceed to the link reaction, then Krebs cycle, and finally the electron transport chain. I did warn you it was a complex process...

In aerobic respiration there will (in an ideal world- which isn't often the case) be a net production of 36 ATP molecules. 38 if you don't subtract the two ATPs needed to start the process during glycolysis.

However, in anaerobic respiration only 2 ATP molecules total will be produced. Nonetheless, the pyruvate molecules will be further modified, for no additional ATP. Don't ask me why. I'm sure there's a valid reason... Anyway, if you happen to be a yeast cell, which would be interesting to say the least, you will convert the 3 carbon pyruvate into ethanol. Since ethanol is a 2 carbon compound, we know that pyruvate was decarboxylated to create ethanol. All in all you produce ethanol and CO2, because of the decarboxylation. I kind of like that word.

If, by the off chance that you are not a yeast cell, but an animal of some sort, you will convert pyruvate into lactic acid (also known as lactate). This is also a 3 carbon compound, so no carbon dioxide is produced. This tends to happen if you have insufficient oxygen during a period of intense exercise. This process also occurs in the cytoplasm, and also results in a net gain of two ATP.

Hehem. Part 2, of the very long, and laborious process of cellular respiration. Also, might I add that the process I am describing is a simplified one. There's actually even more to this than I'm explaining... So yeah. Next step, the link reaction.