deoxyribonucleic acid!?
im in highschool and im obsessed with cell biology. today my teacher opened my eyes.
we have different cells in our body from skin cells to hair cells to mucus cells, and yet each cell has the same instructions(dna) to make the new cell. so why arent our cells all the same? she continued on and talked about proteins but i wasnt paying attention
so how do you other biologists feel when you read that. every cell has the same instructions to make it, and yet they are all different-awesome
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To me this is the beauty of biology. Given the complexity of cells and living organisms it is a wonder it all works pretty well. Im also interested in what happens when things go wrong (eg. cancer).
It is great you are interested in cell biology, keep it up! You should look into epigenetics. I think you would enjoy that. It can be a pretty complex topic though.
The human body is made up of trillions of cells. But one little statistic I find amazing is that they can be organized into only about 210 different types. Like there's skeletal muscle cells and red blood cells and osteocytes and so on, for 210 different types. But 210 different types is enough to make a human being. For some reason, if I had to guess, there's more jobs than 210 that need to be done in the body.
In extremely generalized terms, cells start out as undifferentiated, without a particular job to do, but the chemicals and proteins that they are exposed to make them change, specializing the cells, and these chemical signals also direct the cells to move to the right place in the organism. These signals tell them which genes to use, and which not to use, out of the whole genetic library in their nucleus.
If you're interested in how cells get their different jobs, you should learn about developmental biology. There's a book you might like called Endless Forms Most Beautiful, in which Sean Carroll, a well-known developmental biologist, discusses the processes that shape living things. See if your library has it.
Cells with the same DNA become specialized (differentiate) in different directions, because different genes are turned on or off in different cells.
Each individual gene carries the instructions for making
1 specific protein.
It's the proteins that perform most of the functions in a cell.
In a liver cell, the "liver genes" are turned on, and the cell makes liver proteins.
In a muscle cell, the muscle genes are turned on, but the liver genes are turned off. So the cell makes muscle proteins, and the cell functions as a muscle cell!
Figuring out how these specific genes get turned on or off is the subject of developmental biology - and is a very active area of current research.