The video discusses the process of diffusion, which is a fundamental principle in biology and physics. It explains how diffusion allows organisms to transport necessary resources from the outside to the inside of their cells, a process that is crucial for survival.
The video begins by explaining that life forms must solve the problem of how to transport resources from the outside to the inside of their cells. This process varies depending on the size of the organism. For small organisms like bacteria, diffusion is a free and energy-efficient method of transport. Bacteria consume oxygen to live and produce carbon dioxide as a waste product. Due to diffusion, these molecules spread evenly, allowing carbon dioxide to diffuse out while oxygen is constantly replenished from the outside.
However, this method of "breathing" is only suitable for very small organisms. For larger organisms like insects, a fine network of tracheae, tunnels with a pressure gradient, allows air to circulate slowly and exchange gases with the insect cells. Some insects can contract their tracheae and have specialized breathing organs such as spiracles and air sacs.
The video then discusses the square-cube law, which states that if an organism is made 10 times larger, its outside or surface will grow by 100 times, but its inside or volume will grow by 1000 times. This would make it difficult for the organism to supply its interior with sufficient resources. To overcome this problem, life forms evolved to form multicellular structures, where diffusion works better if there are many small units rather than one much larger unit.
The video concludes by explaining how larger organisms like humans have a lot of blood vessels to reach every cell in the body. Diffusion in the body is effective at about one millimeter, so every cell in the body is at most a mile away from a blood vessel. The video also mentions that large animals need a lot of plumbing complexity to make the process of waste going out and new fuel coming in possible.
The video ends with a partnership announcement with Skillshare, an online learning community that offers courses on almost any creative skill. The video encourages viewers to try something new and get new inspiration, and offers a free trial of Skillshare Premium for the first 1,000 viewers who click on the link in the description.
1. The process of survival involves cells burning glucose molecules with oxygen to provide energy, keeping you alive for another precious moment.
2. Breathing is a solution to the problem of delivering oxygen to your cells that you breathe.
3. The solution to this problem varies depending on one of life's most important controls: size.
4. Living things need lots of different substances to keep them going and they need to move it from the outside to the inside.
5. The first organisms on Earth did not have the abundance of tools and technologies available that life has today after billions of years of evolution.
6. The first life forms were very small, which allowed them to use a free means of transportation based on a physical law called diffusion.
7. Diffusion is the rule of the universe that states that molecules, especially in liquids or gases, are constantly moving in all directions.
8. Bacteria consume oxygen to live, while producing carbon dioxide inside, as a waste product.
9. Due to diffusion, these molecules will eventually spread evenly, thus carbon dioxide diffuses out, while oxygen is constantly replenished from the outside.
10. Insects have a fine network of tracheae, tunnels with a pressure gradient, through which air can circulate very slowly and exchange gases with insect cells.
11. Small organisms have a little interior, or volume, and a lot of exterior, or surface.
12. If we made a bacterium the size of a whale, our giant bacteria would now have a lot of insides and most of what was inside would now be very far from its surface.
13. The size of the cells is limited by the distance over which oxygen and nutrients can effectively diffuse to supply the interior with sufficient resources.
14. Life avoided this problem by forming multicellular structures - organisms composed of many cells instead of a single cell.
15. Diffusion works better if you have many small units rather than one much larger unit.
16. Over time, cell mates began to share work and specialize.
17. The problem of diffusion, superficiality, and energy production remained, limiting the size to which the first multicellular forms of life could reach.
18. Life solved the problem of diffusion by having holes, caves, and tunnels and by folding in on itself, so diffusion can easily occur in every cell.
19. Diffusion in the body is effective at about one millimeter, so every cell in your body is at most a mile away from a blood vessel.
20. Your body has about 100,000 kilometers of capillaries alone, which are the smallest blood vessels, with a surface area of about 1,000 square meters.
21. Your body needs surfaces to take nutrients from your food, so your intestines have an area of half a badminton court, about 40 square meters.
22. The larger you are, the more hidden surfaces you need.
23. Waste goes out and new fuel comes in. Large animals just need a lot of plumbing complexity to make this possible.
24. Fresh Fuel is something we can all use from time to time, especially for our creativity.
25. All it really takes is trying something new and we've got the perfect opportunity to get started.
26. We've partnered with Skillshare, an online learning community that offers courses on almost any creative skill.
27. They have thousands of courses starting at every level, so wherever you are now there will be something for you.
28. You might want to take a look behind the scenes of our animation for example: We've created classes on Skillshare that teach you how we animate scenes from our videos with video tutorials and hands-on projects.
29. Unlimited access to all categories is only ten dollars a month with an annual premium membership.
30. The first 1,000 kurzgesagt viewers who click on the link in the description get a special treat: you'll get a free trial of Skillshare Premium.