Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to curiouskidsus@theconversation.com.
Why do humans and animals have to breathe? – Tennessee, age 7, Hartford, Kentucky
You need to breathe for the same reason you need to eat: It helps you make the energy your body requires.
You probably already know that food is fuel for your body. When you eat, food gets broken down in your stomach and enters your bloodstream.
From there, it gets delivered to your cells. Inside your cells are even tinier structures called mitochondria, which are the engines that power your entire body. Your mitochondria use the nutrients from food as fuel. But to turn it into energy, they need one more ingredient – oxygen.
I am a biologist who studies animals and plants. All living things need oxygen, except for some bacteria and a few tiny animals that don’t. You might be surprised to learn how many ways there are to get oxygen – breathing is only one of them.
Lungs and their linings
When you breathe in, your lungs temporarily trap oxygen, allowing it to pass through very thin surfaces in your lungs into your bloodstream.
Because you need a lot of oxygen, your lungs need a lot of surface area to do their job. They achieve this by having millions of little air sacs lined with tiny blood vessels called capillaries.
If breathing is kind of like eating, why can’t you just take three breaths a day?
One reason is that air on Earth is only 21% oxygen – the rest is mostly nitrogen. That means you need to take five breaths just to get the equivalent of one complete lungful of oxygen.
Also, when you take a breath, only some of the oxygen makes it into your bloodstream. Even though people and many animals make specialized proteins to grab and carry oxygen, there’s a limit to how much they can hold at once. To keep your body’s oxygen levels high enough to power all your cells, you need to keep breathing.
Of course, once you breathe in, you also have to breathe out. The gas you breathe out is called carbon dioxide. You can think of it as the exhaust from your mitochondria engines, the leftovers once the mitochondria burn oxygen and nutrients to release energy.
Other animals and plants
Most living things get oxygen without lungs.
Many aquatic animals use gills, which are sort of like lungs turned inside out. Instead of a bunch of capillaries wrapped around air sacs, gills are a bunch of capillaries sticking out into the water. Just like in your lungs, the blood vessels take in oxygen from the water and release carbon dioxide.
Insects take in oxygen through a network of little air tubes just under their skin, sort of like the chimneys of a building. This system works because insects are small, so the tubes are already close enough to their cells to give them oxygen. When large insects need extra energy, they pump air through the tubes with their muscles.
Plants have little holes in their leaves called stomata. They open and close to let in air when plants need it. Plant roots need oxygen, too, which they usually get from the soil.
You may have heard that plants are the opposite of people: They breathe in carbon dioxide and breathe out oxygen. That’s true because carbon dioxide is a crucial ingredient in photosynthesis – the process plants use to make their own sugar fuel – and oxygen is a byproduct. But plants’ mitochondria also need oxygen to make energy, just like yours do.
Even though most animals and plants don’t breathe in and out the way people do, they all have ways of getting enough oxygen. Learning how organisms solve the same problem in different ways is one of my favorite things about biology.
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Even though people and many animals make specialized proteins to grab and carry oxygen, there's a limit to how much they can hold at once. To keep your body's oxygen levels high enough to power all your cells, you need to keep breathing. Of course, once you breathe in, you also have to breathe out.
Most living things need oxygen to survive. Oxygen helps organisms grow, reproduce, and turn food into energy. Humans get the oxygen they need by breathing through their nose and mouth into their lungs. Oxygen gives our cells the ability to break down food in order to get the energy we need to survive.
The body needs enough oxygen to keep the blood adequately saturated, so that cells and tissues get enough oxygen to function properly. Furthermore, cells and tissues can neither "save up" nor "catch up" on oxygen — they need a constant supply.
All animals breathe to obtain oxygen for their bodies and to expel carbon dioxide, but there are many different ways of breathing. Terrestrial animals generally take in oxygen from the air, while for aquatic animals it usually comes from the water.
All the systems in our body rely on oxygen to make energy. If our blood didn't move the oxygen we breathe into our organs and tissues, we wouldn't be able to carry out normal functions such as moving our muscles, digesting food or thinking.
Fortunately, pet oxygen therapy can significantly improve their quality of life by providing the necessary oxygen to the bloodstream. This valuable therapy reduces breathing difficulties and helps increase exercise tolerance.
Animals need oxygen from air to carry out the reactions that release and transform energy from food. Carbon dioxide is released as a waste product during these processes. In mammals, including humans, air enters the body through the nose and mouth, and moves into the lungs.
Answer and Explanation: The most basic reason why animals need a continuous supply of oxygen is without it animals cannot obtain enough energy from their food. This is because oxygen serves as the terminal electron acceptor in cellular respiration.
We are powered by breathing. Our lungs fuel us with oxygen, our body's life-sustaining gas. Our lungs breathe in air, then remove the oxygen and pass it through our bloodstream, where it's carried off to the tissues and organs that allow us to walk, talk, and move.
The reason animals need a continuous supply of oxygen is to Obtain energy from their food. The most fundamental reason why animals need a non-stop delivery of oxygen is without it animals can't achieve sufficient power from their meals.
Oxygen is essential for life. Normal air contains 21% oxygen, which we breathe into our lungs so it can enter our bloodstream to help with the proper functioning of our tissues and organs. We also breathe as a way to expel carbon dioxide gas, which is a type of waste our bodies produce.
Oxygen is a gas that your body needs to work properly. Your cells need oxygen to make energy. Your lungs absorb oxygen from the air you breathe. The oxygen enters your blood from your lungs and travels to your organs and body tissues.
The primary role of breathing is to absorb oxygen and to expel carbon dioxide through the movement of the lungs. Muscles that control the movement of the lungs are the diaphragm (a sheet of muscle underneath the lungs) and the muscles between the ribs.
Cells need oxygen for the efficient use of glucose in cellular respiration. Most organisms use this method to obtain energy. Oxygen binds to parts of glucose molecules, which release water, carbon dioxide, and energy. After all, this is done, the organism uses the energy to produce adenosine triphosphate (ATP).
The body needs enough oxygen to keep the blood adequately saturated, so that cells and tissues get enough oxygen to function properly. Furthermore, cells and tissues can neither "save up" nor "catch up" on oxygen — they need a constant supply.
If you have a chronic lung disease, you may need additional (supplemental) oxygen for your organs to function normally. Here are some conditions that may require supplemental oxygen, either temporarily or long-term: COPD (chronic obstructive pulmonary disease) Pulmonary fibrosis.
Most living organisms, including plants and animals, require oxygen for life. Organisms need oxygen for cellular respiration, in which energy is released from glucose. Energy is needed by the organism for growth, mobility, and reproduction.
There are few oxidizers as potent as oxygen, and none as readily available. Nitrogen on the other hand is inert due to its extremely strong triple bond and it is therefore not good for a reaction you want to be spontaneous and highly exergonic.
During the process of respiration when an animal breathes, it takes in oxygen gas from the atmosphere and releases carbon dioxide gas back into the atmosphere from the animal's body. During cellular respiration, this carbon dioxide is released as the waste product produced by the animal's cells.
Download image (jpg, 70 KB). Humans and almost all other animals depend on oxygen in the atmosphere or water to respire—that is, to produce energy at the cellular level necessary for survival.
Introduction: My name is Wyatt Volkman LLD, I am a handsome, rich, comfortable, lively, zealous, graceful, gifted person who loves writing and wants to share my knowledge and understanding with you.
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