Phys Lab

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Abstract:

Lauree Sugar Lab 5 100792430 Muscle Contraction

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This experiment was performed to determine the factors that influence muscle contraction and which of the solutions was most effective in doing so. The muscle contraction activity was measured by adding several drops of ATP, Salt and ATP+Salt solutions to each of the myofibrils. We compared the lengths of the muscle measurements before adding the solution and after, to determine how much the muscle contracted. There was no contraction for any of our muscle myofibrils. Introduction: The contraction of muscle fibers is a several molecule process that includes ATP and chloride ions. Muscle contraction is also regulated by the amount of action potential that the muscle receives. There are three basic types of muscle: skeletal, smooth, and cardiac. In this experiment we will look at some of the characteristics of the skeletal muscle tissue. In order for skeletal muscles to contract it to requires a lot of energy. Muscle contraction is driven by ATP and occurs when actin and myosin filaments slide past each other, which is explained by the sliding filament theory. (Rayment et al., 1992). The sliding of the filaments cause acetylcholine(ACh) to be released, which binds to the sodium ion channels, opening them. The opening of these sodium ion channels causes an influx of sodium into the muscle cell, causing the membrane of the muscle cell (sarcolemma)to reduce (Rayment et al.,1992). If this occurs, then an action potential is produced and carried to the sarcoplasmic reticulum where calcium ion channels are opened and calcium is able to bind with troponin. Troponin is a regulatory protein

that is important for muscle contraction. This causes the structure to change, which causes tropomyosin (another protein that works with troponin to aid in muscle contraction) to move and uncover the myosin binding sites on the actin filaments. In this experiment, the glycerin disrupts the troponin/tropomyosin...