Anumber of systems for pumping ions across membranes are powered by atp. such atp-powered pumps are often called atpases, although they do not often hydrolyze atp unless they are simultaneously transporting ions. because small increases in calcium ions in the cytosol can trigger a number of different intracellular reactions, cells keep the cytosolic calcium concentration quite low under normal conditions, using atp-powered calcium pumps. for example, muscle cells transport calcium from the cytosol into the membranous system called the sarcoplasmic reticulum (sr). if a resting muscle cell's cytosol has a free calcium ion concentration of 10-7 while the concentration in the sr is 10-2, then how is the atpase acting?

Viruses are different from bacteria in that they can remain dormant on non-living surfaces they can be found just about anywhere they can infect just about every form of life

Every early childhood education program should develop a

Ms. w, a 21-year-old woman, came into a clinic after suffering a deep laceration on her foot while walking barefoot around her yard. the wound was cleaned, sutured, and bandaged, and she was released to return home after receiving tetanus antitoxoid. within 72 hours, the wound area was red and swollen, the suture line was dark in color, and it was accompanied by severe throbbing pain. ms. w had a high fever, her heart felt like it was racing, and she was finding it hard to concentraten even on simple tasks. she returned to the clinic and was immediately taken to the hospital. following lab tests, a diagnosis of acute necrotizing fasciitis was made. discussion questions 1. explain why ms. w. received a tetanus antitoxoid before leaving the hospital. (see chapters 3 and 4, infection and passive immunity.) 2. explain how acute necrotizing fasciitis developed in this case and the pathophysiology involved. (see acute necrotizing fasciitis.) 3. what is the potential outcome for ms. w if antibiotic drugs do not reduce the infection quickly?