This video demonstrates incredibly complex molecular biology and nanotechnology. The neutrophil chasing a bacteria is a great example of how molecular biology is involved in all physiology, and how important DNA is. For the neutrophil to chase a bacteria it must be able to recognize chemical signals that the bacteria puts out. It must determine that those signals are foreign to the human body, and then it must track the bacteria in order to engulf it. This means there must be specific, directed movement by the neutrophil. The video demonstrates extremely complicated detection, recognition and tracking systems. All of these activities are engineered into the neutrophil and encoded in DNA. Think of how difficult a task you would have if you had to design a system that could detect a harmful organism and be sure it is distinct from useful or needed organisms, then equip that system with the ability to track down a target, and finally destroy it without harming any adjacent normal/needed structures (collateral damage).
This video demonstrates the extremely complicated nanotechnology and molecular biology of one molecule. Notice the very specific 3-dimensional shape that must be achieved for proper function. This 3-D shape is encoded in DNA.