The substance responsible for speeding up the process of chemical reaction in biological systems is –

The substance responsible for accelerating chemical reactions in biological systems is (c) Enzymes. Enzymes are specialized proteins that function as biological catalysts, enhancing the rate of biochemical reactions without being consumed in the process.

Enzymes achieve this by lowering the activation energy required for a reaction to occur, thereby facilitating the formation of the transition state and speeding up the reaction. This acceleration is crucial for maintaining the multitude of biochemical processes necessary for life, including metabolism, digestion, cellular respiration, and DNA replication.

Unlike chemical catalysts, which are often specific to a particular reaction, enzymes exhibit high specificity for their substrates, the molecules upon which they act. This specificity is due to the unique three-dimensional structure of enzymes, which includes an active site where the substrate binds and undergoes catalysis.

Overall, enzymes play essential roles in maintaining cellular function and homeostasis, enabling organisms to carry out vital biochemical processes efficiently.