Question

ATP-PCr system begins with ________, does/does not use oxygen, and leaves ______ as a toxic by product and the limiting factor is?

1) Glycolysis, Lactic Acid
2) Krebs Cycle, Carbon Dioxide
3) Glycolysis, Carbon Dioxide
4) Krebs Cycle, Lactic Acid

Answer 1

The ATP-PCr system is an anaerobic process utilizing creatine phosphate without oxygen to produce ATP quickly for short-term energy, without leaving a toxic byproduct.

Step-by-step explanation:

The ATP-PCr system begins with the phosphorylation of ADP to ATP using creatine phosphate (PCr) and does not use oxygen. This process is anaerobic and happens very quickly, providing energy for short bursts of activity but not leaving a toxic byproduct. The limiting factor for this system is the availability of PCr to donate phosphate to ADP, as it can be depleted quickly during high-intensity bouts of exercise.

Phosphorylation is essential to the processes of both anaerobic and aerobic respiration, which involve the production of adenosine triphosphate (ATP), the "high-energy" exchange medium in the cell. During aerobic respiration, ATP is synthesized in the mitochondrion by addition of a third phosphate group to adenosine diphosphate (ADP) in a process referred to as oxidative phosphorylation. ATP is also synthesized by substrate-level phosphorylation during glycolysis. ATP is synthesized at the expense of solar energy by photophosphorylation in the chloroplasts of plant cells.