No life without enzymes
In biological processes like photosynthesis
that converts sunlight energy into sugar and respiration that converts
sugar into useful cellular energy to sustain life, proteins have
evolved that catalyze chemical reactions in very specific and very
efficient ways. These proteins are called enzymes. Enzymes interact
with reactants converting them into products. This conversion step
may need input of energy to proceed or it can release energy to
do work. Enzymes are the catalysts that control every biological
process of life, with one exception; RNA molecules control and make
proteins.
Many enzymes are membrane proteins.
This means they are part of the natural barrier that separates the
content of a cell from its surroundings. They control transport
of molecules in and out of cells, receive and produce signals that
cells use to communicate with each other, even if they are physically
distant, convert light energy into chemical, and chemical energy
into work, and they catalyze synthesis and degradation of many cellular
structures making sure that old parts are replaced by new ones,
or that invading microorganisms are destroyed before they can destroy
the cell.
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Lukas K. Buehler |