How do cells use energy

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Interactive cell respiration

Whether we sit, walk or stand, dream or think hard - we always use up nutrients. Even now you are consuming nutrients if you read this text and try to understand. The eyes and the brain do not work for free. "The brain steams" is a colloquial expression that expresses very well that energy is consumed in thinking. This energy is made available in complex metabolic processes, which are summarized under the term cell respiration. In the interactive animation, the process of cell respiration exciting and at the same time original way to be explored.

An original look into a mitochondrion, the powerhouse of a cell: Starch is split into many glucose molecules and these continue to react while consuming oxygen.

How interactive animation works


The muscle cells cannot work without energy.

Step by step, the process of cell respiration can be explored in a playful way! To do this, you have to use the mouse to explore the objects on the screen. If you drive over a sensitive surface, it will turn red. Clicking these red colored objects will trigger further actions.

The animation starts with an idyllic scene: a little bird is sitting on a tree. But danger is on the march! A greedy cat approaches and tries to catch the little bird.

A look into the bird's muscle cells reveals that a quick reaction is required! The bird's muscles need immediate energy for a successful escape. This is available in the form of a cherry. To feed the bird, click on the red fruit and drag and drop it into the hungry bird's beak. But be careful: If you react too slowly, the escape fails and the cat eats the poor birdie!


Sensitive surfaces - like the cherry used as bird food here - are colored red in the animation.

After a successful feeding, the bird has an important source of energy - sugar - at its disposal. But only when the sugar is broken down can the muscles do something with the energy. The decomposition process in the mitochondria can then be followed interactively.

To start the animation, the sugar must first be emptied from the box and then shoveled into the kiln. Since the combustion does not work without oxygen, the bellows must now be clicked on. Now the combustion is started and the kiln runs at full speed! Water and carbon dioxide are produced as waste products.

By clicking on the conveyor belt (left in the picture), the energy gained in the combustion can be fed to the muscle cells. Because the mitochondrion has converted the energy stored in sugar in such a way that it can be used by the body. The muscle cells can now work optimally and the little bird manages to escape.

Cell Respiration - Scientific Background


In order for the bird to escape, you have to feed it the cherry.

The name "cell respiration" contains two pieces of information: 1. The energy is provided in the cells; 2. Since it is a respiratory process, the involvement of oxygen is obvious.

If you take a closer look at a cell under the microscope, you will notice that it contains various small "structures", the cell organelles. These organelles include the mitochondria, the "power plants" of the cells. The main steps of cellular respiration take place in the mitochondria: starch is split into many glucose molecules and these continue to react while consuming oxygen.

This reaction with oxygen is similar to the combustion of gasoline in a car engine. Gasoline is burned in the car engine. This consumes oxygen. Exhaust gases and energy are created. In the respiratory chain, nutrients are burned - also with the consumption of oxygen - the "exhaust gases" carbon dioxide and water are created.

The function of cell respiration lies - as in the case of gasoline combustion - in the provision of energy. Burning sugar releases energy that the body needs for its vital processes. For example, the nerve cells of the brain need the energy to think, muscles need the energy to move, etc.


In order to start the combustion, the container with the sugar must first be emptied.

Plants use energy too; the key difference is that plants can generate the energy they use themselves through photosynthesis. Animals need this energy - e.g. B. by eating plants - feed from the outside.

The microscopic image of a plant cell gives us information about how the plant gets its energy. Plant cells also have mitochondria that operate cell respiration. The metabolic processes are the same as in animals. Plants take in oxygen through the stomata of the leaves; Animals and humans ingest it through their mouth, windpipe and lungs.