Question

Enzyme

1. Why are covalent bonds between enzyme and substrate so rare? What kind of bonds do they have?

2. What happens when proteins denature? What environment factors can cause enzymes to denature? What is meant by “optimal” environmental conditions for an organism?

3. Draw a graph showing an exergonic reaction. Label-free energy, ∆G (including the sign “+” or “-“), and the activation energy (E_A). Label the potential energy of the products and the reactants. On the same graph show the difference when enzymes are used for the same reaction. Please label the axes, too.

Answer 1

Ans- Covalent bonds are rare between enzyme and substrate because these are very tight bonds, that will make it very difficult for enzymes to break and form new bonds in substrates leading to formation of products. The bonds formed between enzymes and substrates are non-covalent interactions like hydrogen bonds, electrostatic interactions, hydrophobic interactions and others.

2. When a protein is denatured, it looses its tertiary structure that is important for its functions, leading to protein becoming non-functional.

The environmental factors that can denature enzymes are-

1. Heat- The high temperature breaks non- covalent interactions in enzyme leading to its denaturation.

2. pH- A change in pH leads to protonation and deprotonation leading to disruption of interactions and denaturation.  

Optimal environmental conditions for a organism are the ones at which organism shows maximum growth and for protein, these are the conditions at which protein shows maximum activity.

3.