The smallest unit of life is our most basic unit of organization. In complex lifeforms, cells make up tissues which, make up organs which, make up organ systems which, make up organisms. There are two types of cells:
Cell Parts
There are a few parts of the cell that all cells, prokaryotic and eukaryotic, have in common. These are the cell membrane, cytoplasm, ribosomes, and genetic information, DNA/RNA
Cell MembraneAll cells are surrounded by a fluid barrier that lets substances in and out. It is also called the plasma membrane.All cells have small protein structures that assemble amino acids to make proteins. |
All cells are filled with a jelly-like subsatnce that hold the organelles and other materials in place.All cells have DNA or RNA. |
Eukaryotic Cells Have Membrane-Bound Organelles
Unlike ribosomes which, can be found in all cells, eukaryotic cells have organelles that are surrounded by a membrane similar to the cell membrane. For this reason, many scientist believe that some organelles may have at one time existed on their own as prokaryotic cells.
The DNA of eukaryotic cells in enclosed by the nuclear membrane.Ribosomes can be located on the endoplasmic reiculim which, helps to assemble and transport proteins |
Eukaryotic cells need mitochondria inorder to turn sugar into usable ATP energyProteins are packaged in the Golgi body (or apparatus) |
Differences in Plants and Animals
Plant and animal cells are both eukaryotic, but some of their structures are very different. This is mostly due to the way in which the organisms obtain food. Plants make their own food through photosynthesis and animals need to move in order to find food.
Plant cells have a large, permanent water vacuole.
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Animal cells make small, temporary vacuoles for water and nutrients.
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Plants do not have lysosomes.
(actually the science is up for debate, so for now we'll say they don't until scientists confirm that they do) |
Animal Cells have small structures, full of enzymes, used to break down materials, "cleaning" the cell.
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Plants have green structures that make their own food through photosynthesis
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Animal cell do not have chloroplasts and cannot make their own food
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Quiz yourself with this Cell Parts and Functions Kahoot!