mitochondrion

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Fluorescent confocal image of HeLa cells with green microtubules outlining cell shapes, red mitochondria, and blue nuclei.

The video thumbnail image shows an illustration of an animal cell next to a photo of a whale swimming in the oean.

How Are Plant Cells Different from Animal Cells?

Diagram showing the steps of ATP production in a cell, with glucose entering through the cell membrane, glycolysis in the cytoplasm, and further ATP generated inside a mitochondrion through the tricarboxylic acid cycle and oxidative phosphorylation.

Transmission electron micrograph of partially contracted human striated muscle fiber, showing red bands of actin and myosin filaments and green mitochondria supplying energy.

Diagram of the respiratory chain in metabolism, showing the flow of electrons from NADH and FADH2 through complexes and cytochromes, ending with the reduction of oxygen to water. Key molecules, sites, and electron transfers are labeled.

Cutaway illustration of a eukaryotic animal cell showing labeled internal structures, including the nucleus, nucleolus, mitochondria, endoplasmic reticulum, Golgi apparatus, and other organelles.

Diagram of a mitochondrion cut lengthwise, showing labeled parts including outer and inner membranes, intermembrane space, cristae, matrix, DNA, ribosomes, and membrane protein portions.

Illustration comparing three cell types: a round animal cell and an irregularly shaped plant cell, both showing labeled organelles, and an elongated bacteria cell with labeled structures such as flagella and capsule.

Side-by-side labeled diagrams of a typical animal cell and a plant cell, showing internal structures such as nucleus, mitochondrion, endoplasmic reticulum, and unique features like chloroplasts and cell wall in the plant cell.

At a Glance

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mitochondrion summary

mitochondrion: Media

biology

Videos

The video thumbnail image shows an illustration of an animal cell next to a photo of a whale swimming in the oean.

The Major Parts of an Animal Cell

From teeny-tiny ants to 200-ton whales, all members of the animal kingdom are composed...

Video: Encyclopædia Britannica, Inc.

How Are Plant Cells Different from Animal Cells?

How Are Plant Cells Different from Animal Cells?

All living things are composed of cells.

Video: Encyclopædia Britannica, Inc.

How different parts of a cell interact

How different parts of a cell interact

Learn about the different cell organelles, including the mitochondrion, the nucleus,...

Video: Encyclopædia Britannica, Inc.

Images

Fluorescent confocal image of HeLa cells with green microtubules outlining cell shapes, red mitochondria, and blue nuclei.

mitochondria

Mitochondria (red) are found throughout the cytoplasm of almost all eukaryotic cells...

© defun—iStock/Getty Images

Diagram showing the steps of ATP production in a cell, with glucose entering through the cell membrane, glycolysis in the cytoplasm, and further ATP generated inside a mitochondrion through the tricarboxylic acid cycle and oxidative phosphorylation.

basic overview of processes of ATP production

The three processes of ATP production include glycolysis, the tricarboxylic acid...

Encyclopædia Britannica, Inc.

Transmission electron micrograph of partially contracted human striated muscle fiber, showing red bands of actin and myosin filaments and green mitochondria supplying energy.

mitochondria; striated muscle

A transmission electron micrograph showing a human striated muscle fibre partially...

© BSIP—Universal Images Group/Getty Images

Diagram of the respiratory chain in metabolism, showing the flow of electrons from NADH and FADH2 through complexes and cytochromes, ending with the reduction of oxygen to water. Key molecules, sites, and electron transfers are labeled.

electron-transport chain

The electron-transport chain embedded in the inner membrane of a mitochondrion is...

Encyclopædia Britannica, Inc.

Cutaway illustration of a eukaryotic animal cell showing labeled internal structures, including the nucleus, nucleolus, mitochondria, endoplasmic reticulum, Golgi apparatus, and other organelles.

Eukaryotic cell

Cutaway drawing of a eukaryotic cell.

Encyclopædia Britannica, Inc.

Diagram of a mitochondrion cut lengthwise, showing labeled parts including outer and inner membranes, intermembrane space, cristae, matrix, DNA, ribosomes, and membrane protein portions.

Mitochrondria

A mitochondrion cut longitudinally.

Encyclopædia Britannica, Inc.

Illustration comparing three cell types: a round animal cell and an irregularly shaped plant cell, both showing labeled organelles, and an elongated bacteria cell with labeled structures such as flagella and capsule.

Bacterial, animal, and plant cells compared

Bacterial cells differ from animal cells and plant cells in several ways. One fundamental...

Encyclopædia Britannica, Inc.

Side-by-side labeled diagrams of a typical animal cell and a plant cell, showing internal structures such as nucleus, mitochondrion, endoplasmic reticulum, and unique features like chloroplasts and cell wall in the plant cell.

Organelles of eukaryotic cells

A defining feature of eukaryotic cells is the presence of membrane-bound organelles...

Encyclopædia Britannica, Inc.

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