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Cell Structure | Definitions
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Cell Structure | Definitions
Cell
The cell is the basic unit of all living things.
Cell Membrane
The cell membrane surrounds both animal and plant cells. It holds the contents of the cell in place and controls what enters and leaves the cell.
Mitochondrion
These are tiny rod-shaped structures found inside both plant and animal cells. We refer to them as the 'powerhouse of the cell' because this is where respiration takes place (plural = mitochondria).
Nucleus
The nucleus is found in both plant and animal cells. It's the control centre of the cell and contains the cell's genetic information.
Cytoplasm
The cytoplasm is a watery substance that surrounds the nucleus and all the other cell organelles are suspended in it. It contains important things like water, enzymes, lipids, amino acids, etc. Its main job is to support the other organelles.
Ribosomes
Ribosomes are made of RNA and protein. The function of a ribosome is to make proteins by combining a sequence of amino acids together.
Cell Wall
The cell wall surrounds the entire cell. It is made of the biomolecule cellulose. Cellulose is a rigid material which is good as its main function is to give strength and support to the plant cell.
Chloroplast
The chloroplast is where photosynthesis takes place and chlorophyll is found. The function of the chlorophyll is to absorb the sun's energy during photosynthesis. The plant then uses this energy to make its own food.
Vacuole
The vacuole is a storage organelle. It contains a fluid called cell sap and is used to store substances such as sugars and salt dissolved in water. It gives the cell turgor or strength.
Light Microscope
A light microscope sends a beam of light through the cells which is then focused by the two lenses, the eyepiece and the objective. These are the microscopes we have in school labs and while they magnify specimen very well, you cannot see within cell organelles.
Electron Microscope
The electron microscope sends a beam of electrons through the cells. The images we see from an electron microscope are very clear showing much greater details of the cell structures, for example, we can see the surfaces of organelles like the nucleus in more detail. It has a magnification of up to 10 million times.
Ultrastructure
Ultrastructure is the word used to describe the greater details of a cell that can be seen using an electron microscope.
Prokaryotic Cell
Prokaryotic cells do not have a membrane-enclosed nucleus. Although they have a ring of DNA, it is not enclosed in a nuclear membrane. They also have no membrane-enclosed organelles such as mitochondria or chloroplasts.
Eukaryotic Cell
Eukaryotic cells are much more complex than prokaryotic cells. These cells contain both a membrane-enclosed nucleus and membrane-enclosed cell organelles. The DNA can be found within the nucleus.
Tissue
A tissue is a group of similar cells that are modified to carry out the same function.
Organ
An organ is a structure composed of a number of different tissues that work together to carry out a specific function.
Organ System
An organ system consists of a number of different organs working together to carry out one or more functions.
Biological Organisation
Multicellular living things are organised as follows: cells, tissues, organs, organ systems and organism.
Tissue Culture
Tissue culture is the growth of cells in or on a sterile nutrient medium, outside an organism. The growth of cells outside the organism in an artificial and sterile environment is called in vitro growth.
Cut dotted horizontal lines. Fold vertical line.
Cell
The cell is the basic unit of all living things.
Cell Membrane
The cell membrane surrounds both animal and plant cells. It holds the contents of the cell in place and controls what enters and leaves the cell.
Mitochondrion
These are tiny rod-shaped structures found inside both plant and animal cells. We refer to them as the 'powerhouse of the cell' because this is where respiration takes place (plural = mitochondria).
Nucleus
The nucleus is found in both plant and animal cells. It's the control centre of the cell and contains the cell's genetic information.
Cytoplasm
The cytoplasm is a watery substance that surrounds the nucleus and all the other cell organelles are suspended in it. It contains important things like water, enzymes, lipids, amino acids, etc. Its main job is to support the other organelles.
Ribosomes
Ribosomes are made of RNA and protein. The function of a ribosome is to make proteins by combining a sequence of amino acids together.
Cell Wall
The cell wall surrounds the entire cell. It is made of the biomolecule cellulose. Cellulose is a rigid material which is good as its main function is to give strength and support to the plant cell.
Chloroplast
The chloroplast is where photosynthesis takes place and chlorophyll is found. The function of the chlorophyll is to absorb the sun's energy during photosynthesis. The plant then uses this energy to make its own food.
Vacuole
The vacuole is a storage organelle. It contains a fluid called cell sap and is used to store substances such as sugars and salt dissolved in water. It gives the cell turgor or strength.
Light Microscope
A light microscope sends a beam of light through the cells which is then focused by the two lenses, the eyepiece and the objective. These are the microscopes we have in school labs and while they magnify specimen very well, you cannot see within cell organelles.
Electron Microscope
The electron microscope sends a beam of electrons through the cells. The images we see from an electron microscope are very clear showing much greater details of the cell structures, for example, we can see the surfaces of organelles like the nucleus in more detail. It has a magnification of up to 10 million times.
Ultrastructure
Ultrastructure is the word used to describe the greater details of a cell that can be seen using an electron microscope.
Prokaryotic Cell
Prokaryotic cells do not have a membrane-enclosed nucleus. Although they have a ring of DNA, it is not enclosed in a nuclear membrane. They also have no membrane-enclosed organelles such as mitochondria or chloroplasts.
Eukaryotic Cell
Eukaryotic cells are much more complex than prokaryotic cells. These cells contain both a membrane-enclosed nucleus and membrane-enclosed cell organelles. The DNA can be found within the nucleus.
Tissue
A tissue is a group of similar cells that are modified to carry out the same function.
Organ
An organ is a structure composed of a number of different tissues that work together to carry out a specific function.
Organ System
An organ system consists of a number of different organs working together to carry out one or more functions.
Biological Organisation
Multicellular living things are organised as follows: cells, tissues, organs, organ systems and organism.
Tissue Culture
Tissue culture is the growth of cells in or on a sterile nutrient medium, outside an organism. The growth of cells outside the organism in an artificial and sterile environment is called in vitro growth.