Eukaryotic cells are cells whose DNA is contained in a nucleus surrounded by a nuclear envelope. Animals, plants, fungi and protoctists are all made of eukaryotic cells. Bacteria are prokaryotic: they have no nucleus.Features of eukaryotic cells
• a true nucleus bounded by a double membrane
• membrane-bound organelles, such as mitochondria, endoplasmic reticulum, Golgi apparatus and lysosomes (and chloroplasts in plants)
• linear DNA associated with histone proteins, forming chromosomes
• larger 80S ribosomes in the cytoplasm
• a cytoskeleton of protein filaments
• usually larger size, typically 10 to 100 µm across, compared with about 0.5 to 5 µm for prokaryotic cellsBecause they have membrane-bound organelles, eukaryotic cells are compartmentalised. Different processes, such as respiration in mitochondria and protein modification in the Golgi apparatus, take place in separate compartments, each with its own enzymes and conditions. This allows a larger, more complex cell to work efficiently.Animal and plant cells compared
Both have a nucleus, cell surface membrane, cytoplasm, mitochondria, ER, Golgi apparatus and ribosomes. Only plant cells have a cellulose cell wall, chloroplasts and a large permanent vacuole. Centrioles are found in animal cells but not in the cells of most plants.
Mitochondria and chloroplasts are unusual: they contain their own circular DNA and 70S ribosomes, like bacteria.
• a true nucleus bounded by a double membrane
• membrane-bound organelles, such as mitochondria, endoplasmic reticulum, Golgi apparatus and lysosomes (and chloroplasts in plants)
• linear DNA associated with histone proteins, forming chromosomes
• larger 80S ribosomes in the cytoplasm
• a cytoskeleton of protein filaments
• usually larger size, typically 10 to 100 µm across, compared with about 0.5 to 5 µm for prokaryotic cellsBecause they have membrane-bound organelles, eukaryotic cells are compartmentalised. Different processes, such as respiration in mitochondria and protein modification in the Golgi apparatus, take place in separate compartments, each with its own enzymes and conditions. This allows a larger, more complex cell to work efficiently.Animal and plant cells compared
Both have a nucleus, cell surface membrane, cytoplasm, mitochondria, ER, Golgi apparatus and ribosomes. Only plant cells have a cellulose cell wall, chloroplasts and a large permanent vacuole. Centrioles are found in animal cells but not in the cells of most plants.
Mitochondria and chloroplasts are unusual: they contain their own circular DNA and 70S ribosomes, like bacteria.