ATP is required for the contraction of a sarcomere and thus a muscle fiber. At death, the production of ATP ceases and the ATP stores in a cell are quickly used up. The cell's membranes become permeable to calcium and calcium enters the cytosol of the cell and attaches to troponin, removing tropomyosin from the actin active sites. Myosin attaches to the actin active sites and the muscle contracts for several cycles until the ATP stores are depleted. The muscles are then unable to relax. This postmortem contraction of the muscles is called rigor mortis. Rigor mortis is ultimately caused by a lack of ATP that would, if present, (1) allow calcium to be pumped out of the cytosol and into the sarcoplasmic reticulum and (2) .

Iwill give brainiest to first person who gets it ! what are 3 basic types of interactions we see in an ecosystem?

How did the miller-urey experiment impact the way scientists think about the origins of life? use what you know about the miller-urey experiments to discuss the factors needed for life to arise, and speculate on whether life could arise on another planet.

Where does all the water go? according to the environmental protection agency (epa), in a typical wetland environment, 39% of the water is outflow; 46% is seepage; 7% evaporates; and 8% remains as water volume in the ecosystem (reference: united states environmental protection agency case studies report 832-r-93-005). chloride compounds as residuals from residential areas are a problem for wetlands. suppose that in a particular wetland environment the following concentrations (mg/l) of chloride compounds were found: outflow, 60.4; seepage, 73.7; remaining due to evaporation, 26.4; in the water volume, 46.8. (a) compute the weighted average of chlorine compound concentration (mg/l) for this ecological system. (round your answer to one decimal place.) mg/l (b) suppose the epa has established an average chlorine compound concentration target of no more than 58 mg/l. does this wetlands system meet the target standard for chlorine compound concentration? yes. the average chlorine compound concentration (mg/l) is too high. yes. the average chlorine compound concentration (mg/l) is lower than the target. no. the average chlorine compound concentration (mg/l) is lower than the target. no. the average chlorine compound concentration (mg/l) is too high.