Cells can carry ions across a membrane against the field ("uphill") using a variety of active transport mechanisms. One mechanism does so by using up some of the cell's stored energy converting ATP to ADP. How much work does it take to carry one sodium ion (charge)?

unicellular organisms, like bacteria, are able to perform all life functions within one single cell. multicellular organisms need many different types of cells to carry out the same life processes. each of these special types of cells has a different structure that it perform a specific function.

answer: the correct option is d. enzyme

lactase and carbonic anhydrase are the examples of enzymes.

lactase is an enzyme, which is present in the small intestine of mammals. it in the digestion of the disaccharide, lactose ( milk sugar) by converting it into two monosachharide, which are glucose and galactose.

carbonic anhydrase is present in the red blood cells. this enzyme plays significant role in the transport of co₂. it in the conversion of co₂ and h₂o into carbonic acid, which is then dissociated into bicarbonate ions and hydrogen ions.

cell/ tissue/ organ/ organ system/ body