Aerobic organism facts for kids

An aerobic organism (say "air-OH-bic") is a living thing that needs oxygen to survive and grow. These organisms, also called aerobes, use oxygen to get energy from their food. Think of it like breathing for us – we need oxygen to live! Most animals, plants, and many tiny bacteria are aerobic organisms.

Why Oxygen is Important for Aerobes

Aerobic organisms use oxygen in a process called cellular respiration. This is how they turn food into energy. It's like a tiny power plant inside their cells.

How Cellular Respiration Works

When an aerobic organism eats, its body breaks down the food. Oxygen then helps to release a lot of energy from these broken-down food parts. This energy is stored in a special molecule called ATP. ATP is like the fuel that powers all the cell's activities.

Energy Production with Oxygen

Using oxygen to get energy is very efficient. It creates much more ATP than other ways of getting energy. This means aerobic organisms can grow bigger and do more complex things. For example, humans are aerobic organisms. We need oxygen to run, play, and even think!

Where Aerobic Organisms Live

Aerobic organisms live in places where there is plenty of oxygen. This includes:

• The air we breathe
• Water (like rivers, lakes, and oceans)
• Soil (especially the top layers)
• Inside the bodies of other living things

Examples of Aerobic Life

Many living things you know are aerobes:

• Humans and Animals: We all need to breathe oxygen.
• Plants: They use oxygen for respiration, especially at night.
• Many Bacteria and Fungi: These tiny organisms often need oxygen to thrive.

Different Ways Organisms Use Oxygen

Not all organisms use oxygen in the same way. Scientists group them based on how they deal with oxygen.

Obligate Aerobes: Oxygen is a Must

Obligate aerobes are organisms that absolutely need oxygen to live. They cannot survive without it. If there's no oxygen, they die.

• They gather at the top of a liquid where oxygen is highest.
• Most animals and plants are obligate aerobes.

Obligate Anaerobes: Oxygen is Poison

Obligate anaerobes are the opposite. Oxygen is actually harmful or poisonous to them. They can only live in places with no oxygen.

• They gather at the bottom of a liquid where oxygen is lowest.
• Some bacteria found deep in soil or inside our guts are obligate anaerobes.

Facultative Anaerobes: Flexible with Oxygen

Facultative anaerobes are super flexible! They can use oxygen if it's around, but they can also survive without it. They can switch between using oxygen and other ways to get energy.

• They mostly gather at the top where oxygen is, because it gives them more energy.
• Many types of bacteria, like those found in our intestines, are facultative anaerobes.

Microaerophiles: A Little Oxygen is Best

Microaerophiles need oxygen, but only a small amount. Too much oxygen can actually hurt them. They like a sweet spot with low oxygen levels.

• They gather in the upper part of a liquid, but not right at the very top.
• Some bacteria that cause stomach ulcers are microaerophiles.

Aerotolerant Organisms: Don't Need It, Don't Mind It

Aerotolerant organisms don't use oxygen for energy, but oxygen doesn't harm them either. They can live happily whether oxygen is present or not.

• They are found spread evenly throughout a liquid.
• These organisms get their energy through other methods that don't involve oxygen.

Images for kids

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  Aerobic and anaerobic bacteria can be identified by growing them in test tubes of thioglycollate broth: 1: Obligate aerobes need oxygen because they cannot ferment or respire anaerobically. They gather at the top of the tube where the oxygen concentration is highest. 2: Obligate anaerobes are poisoned by oxygen, so they gather at the bottom of the tube where the oxygen concentration is lowest. 3: Facultative anaerobes can grow with or without oxygen because they can metabolise energy aerobically or anaerobically. They gather mostly at the top because aerobic respiration generates more ATP than either fermentation or anaerobic respiration. 4: Microaerophiles need oxygen because they cannot ferment or respire anaerobically. However, they are poisoned by high concentrations of oxygen. They gather in the upper part of the test tube but not the very top. 5: Aerotolerant organisms do not require oxygen as they metabolise energy anaerobically. Unlike obligate anaerobes however, they are not poisoned by oxygen. They can be found evenly spread throughout the test tube.

See also

In Spanish: Organismo aerobio para niños