There are many species that might go extinct. The one most endangered: White rhinos, with less than 100 in their population. To help these animals, people fund programs like the WildLife foundation. Today, with technology, we haven't had the time to make a change, these people work hard to make sure these animals get proper care and love. :) Hope that helps!
Pepsin is first secreted by the chief cells of the stomach wall and the inactive precursor called pepsinogen. When pepsinogen interacts with the acidic environment of the stomach due to hydrochloric acid, it is turned to pepsin. The pepsin breaks down large protein molecules to smaller molecules.
ATP fuels the primary active transport pump for Sodium and Potassium. The pump maintains a positive voltage on the exterior of the cell and negative on the interior.
The vrtkoff example represents a simplified aircraft taking-off from a runway. There are several viewpoints defined in this model, both static and attached to the plane, allowing you to see the take-off from various perspectives.
