[Biochemistry] Enzymes

What is "Enzymes"?

    Enzymes are proteins that break down the food particles that we eat everyday and form energy. There are many different types of enzymes, for examples, the only enzyme that occurs in the stomach is pepsin which digests proteins such as: meat, vegetable, fruit and many others daily things. If the food we eat is cooked over 118 degree F, it destroys all the enzymes that naturally occur in the food.

   Specially, enzymes act as catalysts and substrates. Each enzyme can only bind to one type of substrate, for example, only glucose can fit to the glycogen active site because they have a right shape. The shape of the enzymes which fits to the other puzzle pieces of enzymes is called active site which splits the substrate. In the stomach, protein digesting enzymes break down bonds and hold the amino acid. The digested protein goes to the small intestine and save energy for supporting our body. The undigested fats in the protein goes too the old intestine and automatically goes out. Fats are digested in the small intestine by the lipase enzyme. For example, glucose protein, that we usually found in the products made from flour, is digested to absorb into a body, it is used up as energy but if it was too much, it will be combined together by special enzymes to form glycogen which is saved to use into another part of bodies. This model of enzyme action is called the lock-and-key model.    Without enzymes, these reactions would take place too slowly to keep our bodies alive. For example, in daily day, we need to eat 3 meals which are breakfast (the most important) then lunch and dinner. If you eat well diet, it is produced fats which help to form energy and support others proteins pumping blood to the brain. When you stop burning fats, you end up damaging your brain. Therefore, enzymes can just only act on one type of molecule. One more fun fact about enzymes is that they are recycled. Only a small amount of enzyme is needed to speed up thousands of reactions.


The optimal pH for enzymes is almost neutral (about 7.3 to 7.4) and it can cause changes in protein structure and shape. For example in the picture below that represented the situation which show the two different enzymes might have two different pH optimal. The green line can represent the glucose protein and the red line can be the pepsin protein.

   Now a day, cancer is the leading cause of death not only in the United States but also in many countries all around the world. Therefore, many scientists want to find the way to end it. In 2006, a group of scientists t Children's Hospital Oakland Research Institute (CHORI) identifies a specific enzyme that can cause the death of cancer cells. Researchers studied the behavior of an enzyme called sphingosine phosphate lyase (SPL), which can regulate cell growth and death by lowering the levels of a natural, growth-promoting lipid called sphingosine-1-phosphate, or S1P. One of the scientists called Dr.Saba said:"Although we're beginning our studies in colon cancer, we believe our research findings will have a direct impact on investigations for other cancers, including pediatric cancers. It is premature to suggest that SPL is the answer to curing cancer, but our research findings should dramatically advance our search for a cure". This experiment has not been used widely but still a big step in medicine for cancer.

References:
Modern Chemistry textbook
https://www.sciencedaily.com/releases/2006/11/061120182022.htm
https://ghr.nlm.nih.gov/primer/howgeneswork/protein

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