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Oligonucleotide
| What it's not: |
A ‘new and improved’ laundry soap. |
| What it is: |
A short fragment of DNA that is 5 to fifty bases long. Oligonucleotides are incredibly useful little things and are found in many techniques. For example, they’re used as primers in PCR and are therefore the starting point of this artificial DNA replication. They’re also fixed to slides or membranes in microarray techniques. Because oligonucleotides are single-stranded, their uses involve hybridizing to a matching single-stranded DNA. |
Operon
| What it's not: |
The King of the Fairies; curiously, also a term for a person undergoing surgery. |
| What it is: |
An operon is a set of adjacent genes under the control of one promoter and synthesized in one piece. The genes are generally related, allowing the cell to respond to an environmental stimulus by using only one regulatory region for several genes. Operons are found in bacteria, with the most famous being the lac operon in E. coli. This operon allows the bacteria to respond efficiently to the amount of lactose in the environment. Luckily, humans are less efficient than bacteria. Although we generally have our genes scattered about under the control of several regulatory regions, this allows us to be more adaptable because our regulatory regions respond to more subtle environments. For example, instead of just responding one way to the amount of lactose, genes may respond differently if there was a high protein level as well – maybe only half the genes would turn on. |
Organelle
| What it's not: |
A tiny keyboard instrument played by women in Victorian parlours. |
| What it is: |
This is subcellular structure in eukaryotic cells with specialized function. Examples include mitochondria, Golgi complex, endoplasmic reticulum, lysosome, peroxisome, and the nucleus. |
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