Cells, atoms and molecules are often referred to in the news and throughout science, but what are they exactly?
Cells are the building blocks of every organic thing on this planet; they cannot be seen with the naked eye and come in all different types, blood cells, skin cells, muscle cells and brain cells. Different cells have different jobs and different structures. Although cells are very small, they can be seen under a microscope, a piece of equipment that magnifies samples. Simple microscopes can magnify up to 400 times, this allows us to see cells such as this:
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For ease of viewing, the samples are stained bright colours so that individual parts can be distinguished. This is a sample of onion tissue and you can see a lot of cells here, each little blue ‘box’ is one cell. The dark blue line is the cell wall, whilst the dark pink circle in the middle of each box is the nucleus.
Cells are like very small bodies in a way, they have what are called organelles. Organelles are simply very small organs that help the cell to live, the most important of these is the nucleus, which is the ‘brain’ of the cell and contains the DNA.
Here is a rough breakdown of the parts of a cell, however, those of ultimate importance as in bold
Animal Cell - http://www.uvm.edu/~inquiryb/webquest/fa06/mvogenbe/Animal-Cell.jpg
Plant Cell - http://micro.magnet.fsu.edu/cells/plants/images/plantcell450.jpg
Cell membrane: This is the ‘skin’ of the cell, it controls what substances, and how much of them move into and out of the cell.
Ribosome: Are little factories which help to create proteins, they float freely around the cell.
Cytoplasm: The cytoplasm is the fluid inside the cell, it gives the cell its shape and allows the movement of nutrients and other organelles.
Nucleus: The ‘brain’ of the cell, it controls cell function.
Goli Body(or Apparatus): The bigger factory within the cell, it produces a variety of cell products.
Smooth Endoplasmic Reticulum: Another factory within the cell which makes the membrane.
Rough Endoplasmic Reticulum: The Rough ER is exactly like the Smooth one except that it has many Ribosomes within it, working together with the ER.
Cell Wall: The cell wall is a tough version of the cell membrane and is found only in plant cells.
Mitochondrion: These organelles convert cell ‘food’ into energy to be used to make more cells, grow and repair (this is called Respiration).
Vacuole: A vacuole is like a giant storage container within plant cells, they can be filled with water or with nutrients and help to give plant cells their stiff shape.
Chloroplasts: Chloroplasts are what make plants appear green, they are the power stations within plant cells and are responsible for absorbing light and making it into plant food.
Whilst cells are the building blocks of living things, atoms are the even smaller building blocks of everything in the world, including cells. Multiple atoms together are called molecules.
Although the atom is far too small to be seen, even with a microscope, scientists have a fairly good idea of what an atom is made up of.
There are 118 known types of atoms and each of these are represented on the Periodic Table of Elements. Elements are the simplest compounds found on Earth – such as gold, silver and helium.
The body parts of an atom are much like that of the solar system – there is a central ball (the sun) and other objects spinning around it (the planets). Within an atom, the “sun” is made up of protons and neutrons – they form the nucleus of the atom. Protons have a positive electric charge, whilst neutrons have no charge. The “planets” are electrons, these have a negative charge. This means that the electrons spin around the nucleus of the atom because they are attracted to the positive chargeof the protons.
A diagram of an atom.
Atoms of either the same type, or of different types can join together to create molecules. For example: two hydrogen atoms (a gas), join to one oxygen atom to create one water molecule – H2O. A glass of water is made up of over a billion water molecules.
A model of a water molecule – two hydrogen and one oxygen atom.
The humble atom and its biological counterpart – the cell, have been studied for years, and will continue to be studied for quite some time I am sure. However, in order to understand some of the exciting and important scientific work and/or moral questions associated with that work, this post should have told you all you need to know.
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