Just needed some clarity for exactly why. Any help would be helpful!

Would yeast ever go through all the stages of respiration as humans? Why?
& also Would humans in general ever go through fermentation as yeast cells do?

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To understand why yeast and humans have different metabolic processes, let's break down the concepts of respiration and fermentation.

Respiration is a process by which cells generate energy from organic molecules, like sugars. In humans, respiration typically occurs in the presence of oxygen and involves a two-step process: (1) glycolysis, which takes place in the cytoplasm, and (2) aerobic respiration, which occurs in the mitochondria. During aerobic respiration, oxygen is used to produce ATP (adenosine triphosphate), the energy currency of cells.

On the other hand, yeast cells can undergo both aerobic respiration and fermentation, depending on the presence or absence of oxygen. Fermentation is an anaerobic process that occurs when oxygen is not available. During fermentation, yeast cells convert sugars into ethanol (alcohol) and carbon dioxide, producing a small amount of ATP.

Now, coming to your questions:

1. Would yeast ever go through all the stages of respiration as humans?

No, yeast would not go through all the stages of respiration as humans. Humans have specialized structures like mitochondria that allow for efficient aerobic respiration using oxygen. Yeast, on the other hand, lack mitochondria and primarily rely on anaerobic fermentation for energy production when oxygen is absent.

2. Would humans in general ever go through fermentation as yeast cells do?

In general, humans do not undergo fermentation like yeast cells. Humans have a well-developed respiratory system that enables them to efficiently utilize oxygen and perform aerobic respiration. However, under certain circumstances, when there is a lack of oxygen supply (e.g., during intense exercise), human muscle cells can switch to anaerobic fermentation temporarily for energy production. This leads to the production of lactic acid, which can cause muscle fatigue and cramps.

In essence, while both yeast and humans can generate energy through different metabolic processes, the specific mechanisms and pathways they employ differ due to their cellular structures and evolutionary adaptations.