To answer your first question yes. In fact a gunshot wound to the lungs while serious is a breath of fresh air when considering the alternatives of a heart or brain GSW.
Normally when associate gun shot wounds we think people die of hemmorhage or destruction tissue, and all things considered it is a possibility (The right Brachiocephalic artery is a major artery supplying the head or and left arm). A nick to artery could kill you pretty fast. Additionally you have the pulmonary arteries and veins which could also kill you through exsanguanation. However these are less likely. Nominally the the lungs do not have so much thick vascularity.
The lungs however do have the consistency of tissue paper, and rely on a vacuum between it and the pleural space in order to breath (Boyle's law; I can explain it if you need just comment). If a hole is punched into the lung especially from a projectile you have the slower risk of bleeding and air going into the space. That space will constanly expand, collapsing the lung, as the patient breathes, untel it vill the entire pleural cavity. However air and blood will continue to leak into the space until eventually it begins to push into onto the other lung and the heart. Thisblife threatening condition is called Pneumothorax or in late stage's where it pushes the heart, a Tension Pneumothorax. This can obstruct the other lungs breathing capacity as well as the hearts ability to pump blood. This causes Obstructive shock and then coma, then death. However this is usually a somewhat slow way to go and can easily be prevented with fast and rapid transport, and applying pressure to the wound (you may still have a whole in the lung leaking air, but by applying pressure you stop the contribution of the hole in of the chest). Nominally in the hospital we'd repair and remove the bullet, suture up the wounds, and decompress the sac and you should be good as new. Usually the process to die can take a while.... Interesting fact, you can see a Pneumothorax as the tracheal will curve toward the healthy lung.
When you are trying to plan for safe exercise goals make sure you are not exercising to much and make sure you are eating and drinking healthy never skip a meal eat 3 times a day and you will be good
The brown stuff is called plaque. This forms on your teeth when you eat and its something you can't get rid of. There is tooth paste that can help maintain it.
The substance that provides immediate energy is adenosine triphosphate (ATP). ATP is called the energy currency of the cell, and is hydrolyzed to produce adenosine diphosphate and a phosphate group. ATP is obtained by break down of carbohydrates, fats as well as proteins.
