During the muscle can no longer physiologically respond, i. e. contract.

The answer to the question, would be: during fatigue.

Explanation:

Normally, a muscle fiber will respond to neurological stimulation to perform movement. In this case, the whole process of movement of the fiber results from the biochemical processes that lead the muscle to respond to calcium and use ATP, so that the chain reactions can be carried out, and the fibers can move. However, there is a point at which, ATP is depleted, and there is an overproduction of lactic acid, which prevents muscle fibers from further responding to stimulation from the motor neuron, regardless of the amount of ACh released to bind with the sarcomeres´ receptors. At this point, then, the muscle fibers are incapable of further responding to stimultation, and thus movement is stopped.

4.) metal

"-the movement of carbon from the nonliving environment into living things and back to the environment

-carbon is the essential component of proteins, fats, and carbohydrates (which make up all organisms)

-carbon exists in air, water, and living organisms

-producers convert carbon dioxide in the atmosphere into carbohydrates during photosynthesis

-bacteria in the atmosphere cycles through the system in filtration units

-in cellular respiration, carbon is released back into the atmosphere as carbon dioxide

-some carbon is stored in limestone (forming one of the largest "carbon sinks" on earth)

-largest carbon reservoir on earth= limestone

-carbon stored in the bodies of organisms as fat, oils, or other molecules may be released into the soil or air when the organism dies

-this may form deposits of coal, oil, or natural gas (fossil fuels, which increased the atmospheric carbon dioxide)

-fossil fuels store carbon left over from bodies of organisms that died millions of years ago

-they are located in the surface of earth, deep within the earth and beneath the ocean floor."