What is the video all about?

You're at the grocery store when, uh oh, . The cold virus is and lands on a cell on your airway lining. Every living thing on Earth is made of cells, from the smallest - to the giant blue whale to you. Each cell in your body is surrounded by a cell membrane, made of fats and proteins, that the inner components. It's , meaning that it lets some thing pass in and out but blocks others. The cell membrane is covered with . They all have functions, like helping cells or binding to nutrients the cell will need. Animal and plant cells have . Only plant cells have a cell wall, which is cellulose that gives the plant structure. The virus cell that was sneezed into your lungs is . , it attaches to a projection on the cell membrane, and the cell brings it through the cell membrane and inside. When the virus gets through, the cell recognizes its mistake. ! Special enzymes arrive at the scene and . They then send one of the pieces back through the cell membrane, where the cell displays it to warn neighboring cells about the invader. A nearby cell sees the warning and immediately goes into action. It needs to make antibodies, proteins that will attack and . This process starts in the nucleus. The nucleus contains our DNA, the blueprint that tells our cells how to make everything our bodies need to function.

A certain section of our DNA contains instructions that tell our cells . Enzymes in the nucleus find the right section of DNA, then create , called messenger RNA. The messenger RNA leaves the nucleus its orders. The messenger RNA travels to a ribosome. There can be as many as 10 million ribosomes in a human cell, a ribbon-like structure called the endoplasmic reticulum. This ribosome reads the instructions from the nucleus. It takes amino acids and links them together one by one creating an antibody protein that will . But before it can do that, the antibody . The antibody heads to the golgi . Here, it's the cell. made of the same material as the cell membrane, the golgi apparatus also gives the antibody directions, telling it how to get to . When it gets there, the bubble surrounding the antibody fuses to the cell membrane. The , and it heads out to track down the virus. The will be broken down by the cell's lysosomes and its pieces . Where did the cell get the energy to do all this? That's the roll of the mitochondria. To make energy, the mitochondria takes oxygen, this is the only reason we breathe it, and adds electrons from the food we eat to make . That process also creates a high-energy molecule, called ATP which the cell uses to power all of its parts. Plant cells make energy in a different way. They have chloroplasts that combine carbon dioxide and water with light energy from the sun to create oxygen and sugar, a form of chemical energy. All the parts of a cell have to work together , and all the cells of your body have to work together to keep you running smoothly. That's a whole lot of cells. Scientists think there are about 37 trillion of them.