These findings suggest that in addition to a voltage-dependent step associated with Na+ translocation, a second voltage-dependent step that is dependent on external, possibly external K+ binding, participates in the overall reaction mechanism of the Na+/K+ pump. Positive Slope Negative Slope Zero Slope Undefined Slope (also known as Infinite Slope). At an extracellular of 1.3 mM, a negative slope was observed at positive potentials. In 90 mM Na+, 5 mM K+ solution, Na+/K+ pump current-voltage curves at negative membrane potentials have a positive slope and can be described by a monotonically increasing sigmoidal function. The occurrence of a negative slope can be explained by the voltage dependence of the apparent affinity for activation of the Na+/K+ pump by external K+, consistent with the existence of an external ion well for K+ binding. Similar results are seen in Na(+)- and Ca(2+)-free solutions in the presence of 2 mM Ni2+, an experimental condition designed to prevent Na+/Ca2+ exchange. If external is reduced below 0.5 mM, negative slopes are observed over this entire voltage range. In Na(+)-free solution containing 5 mM K+, Na+/K+ pump current is relatively voltage independent over the potential range from -160 to +40 mV. Reductions in steady-state current (on the order of 700 nA/cm2) produced by 50 microM ouabain or dihydro-ouabain or by K+ removal, therefore, primarily represent current generated by the Na+/K+ pump. If, in addition, the Na+/K+ pump is blocked by ouabain, K(+)-sensitive currents no larger than 50 nA/cm2 remain. So a line with a negative one slope would look like. That means that if we have a change in x of one, then in order to get negative one here, that means that our change in y would have to be equal to negative one. If we have our change in y over change in x was equal to a negative one. All solutions contained 5 mM Ba2+ and 20 mM tetraethylammonium (TEA) to block K+ channels. A negative slope would mean, well we could take an example. Using the equation y = 3x - 6, set x=0 to find the y-intercept.To investigate the voltage dependence of the Na+/K+ pump, current-voltage relations were determined in prophase-arrested oocytes of Xenopus laevis. It is the point where the line crosses the y axis. The y-intercept of a line is the value of y when x=0.
Slope is the coefficient of x so in this case slope = 3
Slope intercept form y = 7x - 9 becomes 7x - y = 9 written in standard form. Subtract y from both sides of the equation to get 7x - y - 9 = 0Īdd 9 to both sides of the equation to get 7x - y = 9 Note that the equation should not include fractions or decimals, and the x coefficient should only be positive.
Use either the point slope form or slope intercept form equation and work out the math to rearrange the equation into standard form. You may also see standard form written as Ax + By + C = 0 in some references. Find the difference between the y coordinates, Δy is change in y.Here you need to know the coordinates of 2 points on a line, (x 1, y 1) and (x 2, y 2).
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