Cell Structure and Functions
Cell Structure
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All living organisms are composed of cells which can be classified as either prokaryotic (bacteria) or eukaryotic (plants, animals).
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Main components of a typical cell include: cell membrane, nucleus, cytoplasm, mitochondria, and ribosomes.
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Cell membrane, a delicate semi-permeable layer, encases the cell and regulates the movement of substances in and out of the cell.
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The nucleus controls cell activities including growth and reproduction. It contains chromosomes, which are made up of DNA coding for the cell's genetic information.
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The cytoplasm is a jelly-like substance where the cell's metabolic reactions occur, controlled by enzymes.
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Mitochondria, often termed the 'powerhouse' of the cell, generate most of the cell's supply of adenosine triphosphate (ATP), used as a source of energy.
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Ribosomes are minute particles involved in protein synthesis.
Prokaryotic and Eukaryotic cells
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Prokaryotic cells like bacteria are simpler and smaller than eukaryotic cells. They lack a true nucleus and membrane-bound organelles.
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Eukaryotic cells have a defined nucleus enclosed in a nuclear membrane, and feature numerous organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus.
Plant vs Animal Cells
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Plant cells are distinguished by extra components: a cell wall for added support, chloroplasts for photosynthesis, and a large central vacuole storing water and nutrients.
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Animal cells do not have a cell wall or chloroplasts, and instead of one large central vacuole, there are smaller vacuoles scattered throughout the cell.
Cell Functions
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Cells are the building blocks of life and carry out all vital biological processes.
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Functions include growth, replication, energy production, protein synthesis, and waste elimination.
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Every function depends on the cell's ability to take in nutrients, excrete waste, reproduce, and respond to its environment.