As a result of its involvement in a reaction, an enzyme is unchanged.
Enzymes are catalysts that speed up chemical reactions that occur within the biological systems (they increase the reaction rate by lowering its activation energy). Enzymes react with substrate that binds to them (key-lock mechanism) and convert the substrate into the product. Most of enzymes are proteins by their structure but a few are catalytic RNA molecules-ribosymes.
Enzyme activity can be affected by other molecules (activators and repressors), pH, temperature etc.
The phosphate group and the deoxyribose sugar.
More info: the three parts of a nucleotide are the PHOSPHATE GROUP, DEOXYRIBOSE SUGAR, and the NITROGENOUS BASE.
When a Stickleback fish feels threatened, it will flare out its pair of pelvic spines and three dorsal spines, making it difficult for predators to swallow them.
