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E. coli normally metabolise glucose, but if glucose is not available in a new environment, the lac operon can allow E. coli to metabolise lactose, the sugar found in milk using the structural genes beta-gala...

DNA and mRNA are both nucleic acids and are made up of a sugar, phosphates and a base. However, they are very different. Firstly by simply looking at the molecules DNA is double stranded whereas mRNA is sing...

The external intercostal muscles contract which moves the diapraghm upwards. This reduces the volume of the thorax and therefore with less space, the pressure in the lungs goes up. The pressure in the lungs ...

As temperature increases, the molecules involved in the reaction gain kinetic energy, increasing the chances of collision between the substrate molecules and the active sites of the enzymes, a step that is n...

Antigens - cell recognition/cell signalling - receptor or binding site for hormones - cell adhesion - attach to water molecules to stabilise the cell membrane - receptor/ binding site/ trigger