Answer:
I believe that the best answer to the question: How is it that the same tertiary structure of a protein can result from different primary structures? Would be, B: None of the above.
Explanation:
This is probably the best choice from all the ones in the list simply because due to specific portions of the other answers they make the statement incorrect.
It will help to remember this: proteins have primary, secondary and tertiary structures because when they first emerge from the trascription process from mRNA, they are a simple string where the most important factor is the sequence of aminoacids. It is this sequence which will determine the folding factor. However, there is another factor that must always be kept in mind; environmental factors (temperature, medium where the protein is, as well as location where it is being produced) will also play a role on how the folding will happen and on which of the aminoacids.
The evolvement of a protein chain from its primary, to its secondary and then tertiary shape (the only functional, or known as native state) depends on which of the aminoacids in a specific sequence has the necessary elements to form bonds (hydrogen bonds) with others and thus start the folding process.
Answer:
A. If the aerobic pathway—cellular respiration—cannot meet the energy demand, then the anaerobic pathway—lactic acid fermentation—starts up, resulting in lactic acid buildup and "oxygen debt."
C. After about 90 seconds of intense exercise, the muscles become depleted of oxygen, and anaerobic respiration can no longer function to produce ATP, resulting in "oxygen debt."
Explanation:
There are two sources of carbohydrates in the human's body for energy (ATP) production. 1) Creatine phosphate and 2) Glycogen. Creatine phosphate metabolizes easily and yields ATP quickly. Whereas glycogen is stored form of carbohydrate which yields energy more slowly. Therefore, initially, our bodies use creatine phosphate and then shift to glycogen. Within 60-90 seconds, the creatinine phosphate in the body is mostly utilized and then energy is produced by the use of glycogen in aerobic pathway. During areobic pathway, oxygen supply is sufficient and per cycle, it produces 32 molecules of ATP. However, when oxygen supply is limited or absent, the body will metabolize glycogen to lactic acid via fermentation and produce only 2 molecules of ATP.
Now consider the example: Kenny hikes all day at a steady pace therefore the supply of oxygen is sufficient for aerobic cellular respiration for ATP production. In this scenario, the oxygen debt is minimal and Kenny relies on aerobic respiration pathway to obtain energy. On the other hand, Janelle runs fast (100 meters in 13.5 seconds) and her cellular respiration would be on the compense of aerobic pathway initially which will be shifted to anaerobic pathway after the supply of oxygen is reduced/minimum. Janelle will heavily rely on the anaerobic pathway because running fast needs energy which cannot be provided via aerobic pathway easily. Therefore, Janelle's body will produce lactic acid and suffer from oxygen debt.