DNA or deoxyribonucleic acid is a long molecule that contains our unique genetic code. Like a recipe book it holds the instructions for making all the proteins in our bodies. Cells are the basic building blocks of living things.
The human body is composed of trillions of cells, all with their own specialised function. If you have any other comments or suggestions, please let us know at comment yourgenome. Can you spare minutes to tell us what you think of this website? The genetic engineering process A small piece of circular DNA called a plasmid is extracted from the bacteria or yeast cell.
The gene for human insulin is inserted into the gap in the plasmid. This plasmid is now genetically modified. The genetically modified plasmid is introduced into a new bacteria or yeast cell. This cell then divides rapidly and starts making insulin. To create large amounts of the cells, the genetically modified bacteria or yeast are grown in large fermentation vessels that contain all the nutrients they need. The more the cells divide, the more insulin is produced. When fermentation is complete, the mixture is filtered to release the insulin.
The insulin is then purified and packaged into bottles and insulin pens for distribution to patients with diabetes. Related Content:. What is DNA? What is a GMO? This strand contains nucleotides that are complementary to those in the template sequence.
How long does replication take? More on replication. How does DNA polymerase work? What does the molecular structure of a nucleotide look like? What does the lagging strand look like? Watch this video for a summary of DNA replication in eukaryotes.
Key Questions What if an error happens during replication? How is DNA stored in the cell before and after replication? What do the leading and lagging strands look like when they are being replicated? Key Concepts DNA polymerase primer transcription. Topic rooms within Genetics Close. No topic rooms are there.
Browse Visually. Other Topic Rooms Genetics. Student Voices. Creature Cast. Simply Science. Green Screen. Green Science. Bio 2. The Success Code. Scientist use the term "double helix" to describe DNA's winding, two-stranded chemical structure. This shape - which looks much like a twisted ladder - gives DNA the power to pass along biological instructions with great precision. To understand DNA's double helix from a chemical standpoint, picture the sides of the ladder as strands of alternating sugar and phosphate groups - strands that run in opposite directions.
Each "rung" of the ladder is made up of two nitrogen bases, paired together by hydrogen bonds. Because of the highly specific nature of this type of chemical pairing, base A always pairs with base T, and likewise C with G.
So, if you know the sequence of the bases on one strand of a DNA double helix, it is a simple matter to figure out the sequence of bases on the other strand.
DNA's unique structure enables the molecule to copy itself during cell division. When a cell prepares to divide, the DNA helix splits down the middle and becomes two single strands. These single strands serve as templates for building two new, double-stranded DNA molecules - each a replica of the original DNA molecule. In this process, an A base is added wherever there is a T, a C where there is a G, and so on until all of the bases once again have partners.
In addition, when proteins are being made, the double helix unwinds to allow a single strand of DNA to serve as a template. This template strand is then transcribed into mRNA, which is a molecule that conveys vital instructions to the cell's protein-making machinery.
Where is DNA found? What is DNA made of?
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