Cell. External and internal morphology of the eukaryotic cell. Organelles

A eukaryotic cell is larger than a prokaryotic cell, 10 to 100 μm, and its defining feature is the nucleus, which houses the DNA and is surrounded by cytoplasm.

Three membrane-bound organelles carry most of the work: mitochondria for ATP production, the endoplasmic reticulum (rough for protein synthesis, smooth for lipid synthesis), and the Golgi apparatus for sorting lipids and proteins.

Eukaryotic cells are usually multicellular and sometimes unicellular, and are found in animals, humans and plants. Animal cells have a centrosome and lysosomes; plant cells have a cell wall, a central vacuole, chloroplasts and plastids.

The features that define the eukaryotic cell:

• It is larger than a prokaryotic cell, with a size of 10 to 100 μm.
• The nucleus houses the DNA and is surrounded by cytoplasm.
• It is usually multicellular, sometimes unicellular.
• It is found in animals, humans and plants.

Three named organelles and what each is for:

• Mitochondria are for ATP production.
• The endoplasmic reticulum comes in two forms: rough ER for protein synthesis and smooth ER for lipid synthesis.
• The Golgi apparatus is for the sorting of lipids and proteins.

The rough and smooth distinction is worth pinning down now, because it recurs in every later topic: rough ER carries ribosomes and therefore makes protein; smooth ER has none and makes lipid.

Both are eukaryotic, and the differences are a short list.

• Animal cells have a centrosome and lysosomes.
• Plant cells have a cell wall, a central vacuole, chloroplasts and plastids.

Only two rows in that table differ: the cell wall and the plastids. Vacuoles are present in both, although the large central vacuole is a plant feature.