they are biological molecules that significantly speed up the rate of virtually all of the chemical reactions that take place within cells. They are vital for life and serve a wide range of important functions in the body, such as aiding in digestion and metabolism.
Enzymes are a group of proteins. Enzymes control the chemical reactions that take place in a cell. Enzymes are biological catalysts. A catalyst is a chemical which speeds up a reaction without being used itself, it takes part in a reaction but is unchanged and can catalyst more reactions. Cells contain hundreds of different enzymes, each enzyme catalys a different reaction. Everything a cell does depends on which enzyme it can make, which in turn depends on which genes in nucleus are working.
<span>tRNA is actually "transfer RNA". It carries amino acids to the ribosome for protein synthesis. So, it serves as some kind of forklift in the cell - it supplies assembly line with necessary ingredients.</span>
