How do enzymes speed up chemical reactions?
Answer: Some amount of energy must be put in to get the reaction initiated. This energy is required to activate the substances to react. Hence, this energy is called activation energy. In the initial step of the reaction, enzymes by functioning as catalysts, serve to reduce the activation energy required for a chemical reaction to take place. Without altering the process, enzymes speed up the overall rate of reaction.
The enzyme catalytic process has been described in the following stages
- Initially, the substrate binds to the active site of the enzyme, fitting into an active site.
- The binding of the substrate induces the enzyme to alter enzyme shape and it leads to fitting more tightly around the substrate.
- The active site of the enzyme binds to close proximity of the substrate, breaks the chemical bonds of the substrate and the new enzyme-product complex is formed.
- After the reaction, the enzyme releases the final products by decreasing the affinity between enzyme and product.
- Finally, the enzyme is ready to involve in another enzymatic reaction again, this means enzymes can recycle the process by binding the other substrate molecule.
Mostly molecular structures of the enzymes are far larger than reactants (substrate) they act on. However, the active site in the enzyme structure is a very small portion having between 3 to 12 amino acids. The remaining portion of the enzymes has around 20 to 200 and more amino acids, which make up the enzyme bulky and maintain the functioning portion (shape) of the enzymes correctly. This extra part of the enzyme is also very important if the active site is to function at the maximum rate.
Once the enzyme converts the substrate to product, the product no longer fits into the active site, immediately releases into the surrounding medium. Leaving the active site free, welcomes the other substrate molecule to fit into it and which makes the other enzymatic reaction.
To know more about how do enzymes speed up chemical reactions, read these posts: 1) Characteristics of enzymes and 2) Mechanism of enzyme action.
Important questions:
Q. The alpha-helix and beta-sheet are found at which level of protein organization?
Q. Which cytoskeletal proteins provide the structural support for microvilli?
Q. Which of these does not contain a structural protein?
Q. What level of protein structure is associated with the sequence of amino acids?
Q. Which of the following pertains to typhoid fever?
Q. Which of the following tests is an agglutination test for the bacterium causing typhoid fever?
Q. This is a compound made from a group of covalently bonded atoms?
Q. If two covalently bonded atoms are identical the bond is?
Q. Which of the following are characteristics of G protein-coupled receptors (GPCR)?
Q. What are the second messengers in the GPCR-phospholipase c signal transduction system?
Q. Which of the following have a significant influence on a material’s electrical resistivity?
Q. What are alleles? And an example.
Q. What is one difference between DNA replication of bacteria and eukaryotes?
Q. Which of the following genotypes is homozygous recessive?
Q. If q = .4, what is the frequency of homozygous recessive individuals?
Q. A person who is homozygous recessive at a locus has which of the following?
Q. If cohesin was not produced or not functional what would be the effect on mitosis?
Q. Which of these is a reverse transcriptase?
Q. Which of the following functions as cell identity markers, receptors, and enzymes?
Q. Which cytoskeletal proteins provide the structural support for microvilli?
Q. The alpha helix and beta-sheet are found at which level of protein organization?
Q. Thermogenin in the inner membrane of brown fat cell mitochondria does all of the following except?
Q. What is ATP synthase and what does it do?
Q. Brown fat cells produce a protein called Thermogenin
Q. Which of the following eukaryotic cell structures plays a role in protein trafficking and sorting?
Q. Which of these does not contain a structural protein?
Q. After which checkpoint is the cell first committed to continuing the cell cycle through M?
Q. Which of the following statements about ATP (adenosine triphosphate) is correct?
Q. What happens in the G1 phase of the cell cycle?
Q. In general, enzymes are what kinds of molecules?
Q. The junction between the axon of one neuron and the dendrite of the next is called
Q. What is the role of enzymes in the DNA replication process?